Articles de revues : « Excavation (process) »

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Lee, Joosung, Byeol Kim, Dongik Sun, Changsoo Han et Yonghan Ahn. « Development of Unmanned Excavator Vehicle System for Performing Dangerous Construction Work ». Sensors 19, n^o 22 (7 novembre 2019) : 4853. http://dx.doi.org/10.3390/s19224853.

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Of all the machinery and equipment used on construction sites, excavators are responsible for the greatest number of fatal accidents. Excavation is an inherently risky process due to imprecise work processes and the unstable external environment on most work sites. The resulting accidents cause serious injuries that threaten the lives of not only the excavator pilots but also those working around them. In this study, we propose a mechanical device that is capable of operating the excavator remotely from a nearby safe location such as a site office. To ensure worker safety and at the same time boost the productivity of excavation operations, data from 3D scanners, cameras, and sensors were combined to create a detailed 3D picture of the area surrounding the excavation site to guide a remotely operated excavating system. Rather than modifying the excavator itself, a removable manipulator was mounted on the joystick in the excavator’s cockpit. Our proposed system was tested on a standard commercial excavator to verify its performance for a real-world excavation task.

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Lukashuk, Olga A., et Konstantin Iu Letnev. « Determining operation parameters of the leverage mechanism in a mining excavator ». Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal 1 (30 mars 2021) : 94–102. http://dx.doi.org/10.21440/0536-1028-2021-2-94-102.

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Introduction. The paper analyzes the process of rock excavation using a front-shovel operational equipment of an open-pit excavator in the context of determining rational modes of operation for its main mechanisms (lifting and thrusting mechanisms) during the excavation. The main purpose of the study is to establish the kinematic and dynamic characteristics of the excavation process by identifying patterns of changes in the operating parameters of the main mechanisms. Research methodology includes mathematical modelling and computational experiment with the use of machines and mechanisms theory methods. Results. Dependencies were obtained to determine rational values of lifting and thrusting velocities which ensure that the bucket (top of its cutting edge) moves along a specified trajectory while excavating. A simulation model was built for the process of rock excavation carried out by front-shovel excavators, which represents a set of calculated values for the operational parameters of the main mechanisms to realize the bucket movement along a specified path and provide specified energy-force parameters on the bucket. An optimizing algorithm was developed to control the working process of an open-pit excavator and achieve required values of the operation parameters to get the bucket moving at a specified excavating velocity within the work area of the excavator. It is shown that their joint action forms a kinematic chain which connects the main mechanisms and the bucket and includes driven links of those mechanisms and elements of the operational equipment. Operation parameters of the main mechanisms were found to be formed in accordance with kinematic properties of the transmission mechanism (with the kinematic chain as its part). Scope of results. The results of the research could be used to develop a control system for the drives of the main mechanisms.

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Zhou, Zhangtao, Zheming Zhu, XinXing Jin et Hao Tang. « Numerical Prediction of Rock Fracturing During the Process of Excavation ». International Journal of Geotechnical Earthquake Engineering 1, n^o 2 (juillet 2010) : 12–23. http://dx.doi.org/10.4018/jgee.2010070102.

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During the process of excavation, blasting can induce cracking inside the surrounding rock. Considering the effects of material properties and loading conditions, a rock blasting excavation model with two successive excavation steps was developed through the use of AUTODYN code. Four kinds of equation of state (EOS), linear, shock, JWL, and compaction were applied to the materials employed in this numerical model. A modified principal stress failure criterion was applied to determining material statuses, and TNT explosive and a relatively homogeneous igneous rock, diorite, were used in this numerical model. By using this numerical model, rock fracturing process during blasting excavation was simulated, and rock fracturing process during two successive excavations is presented.

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Qin, Zuhe. « Modeling and Simulation of Theoretical Digging Force of an Excavator Based on Arbitrary Posture ». Mathematical Problems in Engineering 2022 (10 septembre 2022) : 1–7. http://dx.doi.org/10.1155/2022/8030349.

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Theoretical digging force is an important performance parameter of the hydraulic excavator. Due to the multi-linkage mechanism, the digging posture of an excavator is ever-changing; thus, it is not easy to calculate the theoretical digging force. Traditionally, the theoretical digging force is calculated by selecting a limited number of postures of the excavator based on experience, which cannot reflect the force condition of each posture in the excavation process. In order to calculate the theoretical digging force of any posture in the excavation process, this paper uses the principle of the analytical method to establish a theoretical excavation force mathematical model of bucket excavation and uses Matlab software to solve the theoretical excavation force mathematical models. In order to verify the model’s correctness, the experimental method is used to determine the actual maximum excavation force of the excavator. The test results showed that there was little difference between the actual maximum digging force and the theoretical maximum digging force, which verified the correctness of the theoretical digging force mathematical models and provided a theoretical digging force calculation method and reference for the structural design and optimization of the excavator.

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Yang, Zi Sheng, Jun Xia Liu et Yi Ren Wang. « Weight Analysis of Accident Factors in Deep Foundation Excavation Based on Analytic Hierarchy Process ». Applied Mechanics and Materials 711 (décembre 2014) : 529–34. http://dx.doi.org/10.4028/www.scientific.net/amm.711.529.

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For the past few years, great development has been achieved in deep foundation excavation. However, due to foundation excavation’s locality, individual diversity, complexity and uncertainty, the probability of accidents in foundation pit engineering tends to be greater than that in main works, and the accident rate may even reach about 20%, which makes the study on factors leading to foundation excavation accidents quite necessary and meaningful. By use of Analytic Hierarchy Process (AHP), this paper has figured out the ratio (weight) of the investigation, design, construction and other factors leading to foundation excavation accidents to the whole factor set, which is of great guiding significance to the study on prevention and treatment of foundation excavation accidents in future.

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Li, Shen Gang, Wen Zhao, Xiao Li Cai, Yin Fu Ma et Lu Zhang. « Research on Stability in Metro Tunnel Constructing with Shallow Buried Covered Excavation in Loose Sand Layers ». Advanced Materials Research 594-597 (novembre 2012) : 1240–44. http://dx.doi.org/10.4028/www.scientific.net/amr.594-597.1240.

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For subway tunneling in urban underground, high safty of construction is needed.However, the safty and rationality of excavating plan are forecasted difficultly because of consealment. Based on the Zhang-Shen tunnel construction of Shenyang subway, bench method, single side-wall heading excavation method and CD excavation method are numerical simulated; according to the numerical calculation results and the constructing process, bench method is adopted; the ground settlement caused by excavation monitored during excavating is in the allowed range and the tunnel is safe during excavating.

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Shemiakin, Stanislav. « Determining the maximum turning force of the hydraulic backhoe excavator bucket ». Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal, n^o 3 (20 juin 2023) : 17–24. http://dx.doi.org/10.21440/0536-1028-2023-3-17-24.

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Introduction. Single-bucket excavators with both flexible and rigid suspension of work equipment are actively engaged in construction, stripping work and production mining. Excavators with rigid suspension are commonly used in construction, while excavators with flexible suspension are used in mining practice. This work considers the process of excavating rock with a single-bucket hydraulic backhoe excavator. The reliability and durability of excavators depend on the correct choice of the parameters of work equipment elements. Research objective is to determine the maximum turning force of the bucket of a hydraulic backhoe excavator, taking into account soil friction against the bucket bottom and side plates during rock excavation. Methods of research. When the maximum force on the bucket turning hydraulic-cylinder rods in the course of rock excavation is analytically defined, it is advisable to consider digging a trench in plain surface or in the open-pit in plain surface of a stope face provided that per one turn the bucket is filled to capacity. In this case, a segment of soil cut from the rock mass has maximum depth of cut as compared to other excavation methods. Total excavation resistance includes: resistance arising from cutting rock with a bucket with maximum depth of cut; resistance associated with the impact of gravity of the rock mass on the bucket; resistance associated with rock mass friction against the bucket bottom; resistance associated with rock mass friction against the inner surfaces of the bucket side plates. Results. The dependence has been determined between the maximum force on the bucket turning hydraulic-cylinder rods and bucket design parameters as well as the physical and mechanical characteristics of the face rock. The results analysis showed that both excavation process flow scheme and rock characteristics have a significant influence on the total bucket excavation resistance. Conclusions. The developed method of calculating the excavation resistance takes into account the internal forces of bucket interaction with rock and makes it possible to increase the accuracy of maximum digging force calculation. It therefore becomes possible to more reasonably approach the choice of the excavator bucket turning hydraulic cylinder parameters and thereby increase the reliability and durability of the machine as a whole.

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Mu, Linlong, Jianhong Lin, Zhenhao Shi et Xingyu Kang. « Predicting Excavation-Induced Tunnel Response by Process-Based Modelling ». Complexity 2020 (28 avril 2020) : 1–11. http://dx.doi.org/10.1155/2020/9048191.

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Potential damages to existing tunnels represent a major concern for constructing deep excavations in urban areas. The uncertainty of subsurface conditions and the nonlinear interactions between multiple agents (e.g., soils, excavation support structures, and tunnel structures) make the prediction of the response of tunnel induced by adjacent excavations a rather difficult and complex task. This paper proposes an initiative to solve this problem by using process-based modelling, where information generated from the interaction processes between soils, structures, and excavation activities is utilized to gradually reduce uncertainty related to soil properties and to learn the interaction patterns through machine learning techniques. To illustrate such a concept, this paper presents a simple process-based model consisting of artificial neural network (ANN) module, inverse modelling module, and mechanistic module. The ANN module is trained to learn and recognize the patterns of the complex interactions between excavation deformations, its geometries and support structures, and soil properties. The inverse modelling module enables a gradual reduction of uncertainty associated with soil characterizations by accumulating field observations during the construction processes. Based on the inputs provided by the former two modules, the mechanistic module computes the response of tunnel. The effectiveness of the proposed process-based model is evaluated against high-fidelity numerical simulations and field measurements. These evaluations suggest that the strategy of combining artificial intelligence techniques with information generated during interaction processes can represent a promising approach to solve complex engineering problems in conventional industries.

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Wu, Shan, Jian Wu et Dunwen Liu. « Research on Construction Sequences and Construction Methods of the Small Clear-Distance, Double-Arch Tunnel under an Asymmetrical Load ». Applied Sciences 13, n^o 14 (16 juillet 2023) : 8242. http://dx.doi.org/10.3390/app13148242.

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A small clear-distance, double-arch tunnel under an asymmetrical load combines the characteristics of small clear-distance, tunnels and double-arch tunnels, and the influence of an asymmetrical terrain must be considered. Its construction stability is a problem worth studying. This paper used the Wengcun tunnel as the engineering background. Midas/GTS finite element analysis software was used to study the effects of eight excavation sequences and two excavation methods on tunnel stability. The results showed that the deformation and force of the tunnel were asymmetric under the asymmetrical terrain. Both middle partition walls were deformed towards the shallowly buried side, and the shallowly buried side was deformed to a greater extent. Excavating shallow side tunnels first can effectively mitigate the impact of asymmetric terrain. The arch settlement of the Center Diaphragm Excavation Method is 1.33 cm, which is smaller than the three-step excavation method of 1.48 cm; however, this difference is not significant. The Three-bench Excavation Method was more efficient. Based on the conclusion of a numerical simulation, the construction site adopted the construction sequence of excavating the shallowly buried side tunnel first and adjusted the excavation method to the Three-bench Excavation Method.

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Wang, Yong, Linlin Wang, Chenchen Li, Ziao Xue, Yuan Sun, Ruiyong Ma, Dagang Wang et al. « Optimization of Excavator Bucket Structure by a Coupled Simulation Method ». Applied Sciences 13, n^o 20 (16 octobre 2023) : 11336. http://dx.doi.org/10.3390/app132011336.

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As a component directly in contact with materials in the excavation process of the excavator, the structure and performance of the bucket directly affect the efficiency of the excavator. With the increasingly prominent environmental and energy problems, it has become a research difficulty to optimize the bucket structure of excavators so as to reduce the digging resistance and energy consumption of excavators. Therefore, an orthogonal optimization method of bucket structure that couples Adams with EDEM was proposed to explore the excavation performance of buckets with different structures under different geological conditions. The particle size distribution and mass proportion of various ores under different geological conditions were obtained through geological investigation, and particle models with different shapes and sizes were constructed. The friction coefficient and collision recovery coefficient between bucket and ore and between ore and ore were measured using a self-made testing device. The results show that the excavation resistance of the bucket teeth during the excavation process is much greater than that of other components, and optimizing the bucket structure can effectively reduce the excavation resistance of the bucket teeth. Under different geological conditions, the optimization parameter combinations of bucket structure obtained through orthogonal experiments are different. In addition, after structural optimization, the excavation resistance and energy consumption of the bucket were reduced, and the filling rate was also improved.

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Komissarov, Anatoly P., Yuliya A. Lagunova et Olga A. Lukashuk. « SOFTWARE MANAGEMENT OF THE ROCK EXCAVATION PROCESS BY A QUARRY EXCAVATOR ». Mining Equipment and Electromechanics, n^o 5 (23 décembre 2020) : 28–33. http://dx.doi.org/10.26730/1816-4528-2020-5-28-33.

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ISHIKAWA, Masato, Takanobu ASHIDA, Taito HARAGUCHI, Tetsu OGAWA et Taisuke KUSABA. « Model of the excavation process for efficiency of the hydraulic excavator ». Proceedings of JSME annual Conference on Robotics and Mechatronics (Robomec) 2016 (2016) : 2A2–08b5. http://dx.doi.org/10.1299/jsmermd.2016.2a2-08b5.

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Arabaninezhad, Arefeh, et Ali Fakher. « A framework for the use of reliability methods in deep urban excavations analysis ». Acta Geotechnica Slovenica 18, n^o 1 (2021) : 2–14. http://dx.doi.org/10.18690/actageotechslov.18.1.2-14.2021.

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Deep excavations in urban areas impose deformation to adjacent structures; hence the reliability of deformation analysis for the real deep excavation projects is very important to be assessed. In this study a framework is presented for the use of reliability methods in deformation analysis of deep urban excavations. The suggested framework is applied for 5 real deep excavation projects implemented during last 10 years. All studied cases were recognized as projects of high importance in urban areas, and were monitored during the excavation process. A non-probabilistic reliability analysis procedure, Random set method, in combination with finite element numerical modeling is applied to obtain the probability of unsatisfactory performance for each case. The reliability analysis results are confirmed by field observations and measurements. Typical results for the probability of analytical deformations exceeding the acceptable values along with the site observations and measured displacements for 5 real deep excavation projects show that the reliability analysis could be a beneficial tool for designer. It is concluded that applying the suggested framework in the design stage of deep excavation projects may lead to design more appropriate systems compared to common deterministic design methods.

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Fu, He-Lin, Huang-Shi Deng, Yi-Bo Zhao, Xiao-Bing Chang et Hai-Dong Yi. « Study on the Disturbance of Existing Subway Tunnels by Foundation Sloping Excavation ». Applied Sciences 13, n^o 2 (10 janvier 2023) : 948. http://dx.doi.org/10.3390/app13020948.

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Urban subway tunnels are located in a very complex operating environment, and the surrounding construction disturbances can lead to the deformation of existing tunnels or even produce tunnel disease issues. The disturbance of adjacent tunnels by pit excavation is an important geotechnical issue among scholars. In our study, the two-stage method is used to derive the deformation of the existing tunnel caused by the use of sloping excavation in the foundation pit. Subsequently, the correctness of the theoretical calculation formulae and the results are verified by constructing numerical calculation models. The effects of different slope footings θ, different slope widths b and different excavation depths H on the deformation of the existing tunnel are analyzed. The results show that: the excavation of the foundation pit can effectively reduce the tunnel deformation by using the sloping excavation method. The soil directly above the tunnel is the main factor causing the deformation of that tunnel. When the foundation pit spans a single-lane existing tunnel, the sloping excavation method of excavating soil on both sides and reserving the middle core soil can be used. When the foundation pit spans a double-lane existing tunnel, the sloping excavation method of excavating the middle soil and reserving core soil on both sides can be adopted. The error between the theoretical calculation results and the numerical simulation results is small, which verifies the correctness of the theoretical calculation results. The load distribution width of the soil after sloping excavation can be taken as the median line width. The deformation of the existing tunnel is influenced, to a greater extent, by changes in the one-time excavation depth H and slope width b, and to a lesser extent, by changes in the slope angle θ.

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González-Quiñones, Juan José, Juan Francisco Reinoso-Gordo, José Antonio Solano-García, José Miguel Cámara-Donoso, Carlos Alberto León-Robles, Gonzalo Linares-Matás et Juan Manuel Jiménez-Aren. « Monitoring an archaeological excavation using photogrammetry and digital elevation models (DEMS) : the case study of Barranco León in Orce (Granada, Spain). » SPAL. Revista de Prehistoria y Arqueología de la Universidad de Sevilla, n^o 31.2 (2022) : 10–30. http://dx.doi.org/10.12795/spal.2022.i31.18.

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In this paper, we describe and discuss emergent digital technologies employed for monitoring the excavations at the archaeological site of Barranco León (Granada, Spain) between 2017 and 2020. The method entails the following material requirements: a total station, a conventional camera, a computer and a software that integrates photogrammetry algorithms; in terms of human resources, the presence of an engineer for the first day of the excavation to set up the methodological process and trained excavation staff to perform said method on a daily basis is necessary. Here we present the daily workflow for monitoring archaeological excavations introduced at the site, followed by an estimation of the costs and a summary of the results obtained. The method introduced here is based on the height difference of Digital Elevation Models (DEMs) computed on successive days using photogrammetric techniques. It is a non-invasive method, which requires less than 8% of the economic resources of the excavation and can be carried out in less than 15 minutes. This allows the excavation director to have an accurate and visual idea of the excavation process in order to make appropriate decisions. In addition, from the results obtained in the method (differences in DEM of every two days), other derived results can be obtained such as the exact location of the archaeological remains extracted based on their size. These features highlight the relevance and applicability of this approach to a wide range of archaeological sites.

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Sanders, Donald H. « Enabling Archaeological Hypothesis Testing in Real Time using the REVEAL Documentation and Display System ». Virtual Archaeology Review 2, n^o 4 (20 mai 2011) : 89. http://dx.doi.org/10.4995/var.2011.4560.

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<p>This paper focuses on a system that can ensure that excavations are indeed fully documented and that the record is accurate. REVEAL is a single piece of software that coordinates all data types used at excavations with semi-automated tools that in turn can ease the process of documenting sites, trenches and objects, of recording excavation progress, of researching and analyzing the collected evidence, and even of creating 3D models and virtual worlds. Search and retrieval, and thus testing hypotheses against the excavated material happens in real time, as the excavation proceeds. That is the important advance.</p>

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Li, San-Ping, Hai-Bin Lin, Li-Guo Wu, Wen-Quan Bao et Jia-Mei Qi. « Innovative Design and Mechanical Analysis of Low-Resistance Fritilariae Ussuriensis Maxim Excavation Device ». Applied Sciences 13, n^o 18 (11 septembre 2023) : 10204. http://dx.doi.org/10.3390/app131810204.

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Fritilariae ussuriensis maxim can be used as a medicine with little difficulty in its planting, but owing to its fragile characteristics, Fritilariae ussuriensis maxim is mainly collected by manual excavation. In order to solve the problems of the low working efficiency and poor environmental adaptability of the harvesting equipment of Fritilariae ussuriensis maxim, this paper designs a new excavation device, which can effectively reduce the operation resistance and improve the excavation efficiency of Fritilariae ussuriensis maxim. In this paper, the finite element method and discrete element method are used to simulate and analyze the operation performance of the excavation device. Combined with the orthogonal test and single factor test, the factors affecting the operating performance of the excavating device were explored. The excavating experimental platform was designed and built, and the simulation results were verified with experimental excavation data. This study shows that the operating speed, shovel face inclination angle, and digging depth had significant effects on the digging resistance of the shovel body, with the shovel face inclination angle having the highest influencing factor and the operating speed having the lowest influencing factor. Combined with the orthogonal test analysis and response surface design, the optimal operating parameters of the shovel body are: operating speed 0.5 m/s, shovel face inclination angle 25°, and excavation depth 120 mm.

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MOON, Sungwoo, et Jongwon SEO. « VIRTUAL GRAPHIC REPRESENTATION OF CONSTRUCTION EQUIPMENT FOR DEVELOPING A 3D EARTHWORK BIM ». Journal of Civil Engineering and Management 23, n^o 8 (20 novembre 2017) : 977–84. http://dx.doi.org/10.3846/13923730.2017.1348981.

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BIM provides a visualization of the construction design that allows a construction manager to review the construction process and the information that is associated with the progress. BIM is usually applied to modeling structural objects with parametric geometry where the sequence of process can be predefined. However, BIM technology can also be applied to objects with irregular shape where parametric modeling is not possible such as earthwork topography based on TIN (Triangular Irregular Network).The objective of this research is to develop a 3D earthwork BIM methodology and provide a graphic simulation that is capable of assisting construction equipment operators during excavation work. The 3D earthwork BIM presents a modeling technique that involves integrating hardware and software technologies. This combination of technologies is used to represent the actual excavator configuration in a 3D virtual environment. When it is applied to actual excavation work, it was proved that the 3D earthwork BIM could synchronize the virtual excavator configuration with the actual excavator configuration during excavation work in real time.

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Li, Zan, Songyu Liu, Kai Wu et Taishan Lu. « Analysis on Response of a Single Pile Subjected to Tension Load Considering Excavation Effects ». Applied Sciences 12, n^o 13 (2 juillet 2022) : 6717. http://dx.doi.org/10.3390/app12136717.

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With the development of urbanization, numerous excavations are carried out to facilitate the development of underground space. As a support for tunnel structures, uplift piles are often installed prior to tunnel excavation. The excavation inevitably causes disturbance to the soil below the excavation surface, changing the soil’s mechanical behavior and stress state significantly. However, there is still a lack of a method to evaluate the change in pile capacity due to excavation. This paper proposes a semi-analytical approach for estimating the change in load-settlement behavior of an uplift pile considering the effects of excavation. A hyperbolic model was adopted to simulate the nonlinear interaction of the pile–soil interface. The nonlinear shear-induced soil displacement outside the pile–soil interface is introduced to obtain a more realistic load-displacement behavior of the uplift pile. An effective iterative program was implemented based on the proposed semi-analytical approach. The comparisons between the results from the proposed methods, well-documented field tests, centrifuge tests, and other analytical methods showed that the proposed approach is suitable for analyzing an uplift pile considering excavation effects. A parametric study was conducted to investigate the effects of main soil properties on the pile capacity loss caused by excavation. The results showed that the soil friction angle and the ratio of the excavation depth to the pile effective length have a great influence on the loss in pile uplift capacity caused by excavation. However, the loss of pile uplift capacity caused by excavation is not affected by the soil’s shear modulus or Poisson’s ratio.

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Kong, Suk-Min, Yoseph Byun, Sang-Il Choi, Chang-Yong Kim et Seong-Won Lee. « A Study of Vibration Reduction Effects of TBM and NATM Parallel Construction Methods according to Tunnel Depth and Size ». Applied Sciences 13, n^o 6 (9 mars 2023) : 3492. http://dx.doi.org/10.3390/app13063492.

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The new Austrian tunnelling method (NATM) and tunnel boring machine (TBM) are methods for excavating underground spaces. The NATM construction method has noise and vibration problems, and excavation using TBM has the disadvantage of high initial cost and is limited by ground conditions. A parallel TBM and NATM construction method has been developed to overcome these limitations. However, research on the TBM and NATM parallel construction method is lacking, and it is crucial to identify the applicability of the TBM and NATM parallel construction method in advance by applying it to various ground and blasting conditions. In this study, based on the vibration measurement data of the excavation site using the NATM construction method, the vibration measurement values generated when excavating the top surface using the existing NATM construction method and the TBM and NATM parallel construction methods were compared. Lastly, the vibration reduction effect of the two construction methods was analysed according to the tunnel excavation depth and tunnel size through 3D numerical analysis. As the depth of tunnel excavation increases, the vibration at the ground surface is reduced by up to 83%. In addition, as the ratio of the size of the blasting surface with NATM and the excavation surface with TBM is closer to 1.0, the vibration decreases.

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Rehman, Hafeezur, Abdul Muntaqim Naji, Kyoungmin Nam, Saeed Ahmad, Khan Muhammad et Han-Kyu Yoo. « Impact of Construction Method and Ground Composition on Headrace Tunnel Stability in the Neelum–Jhelum Hydroelectric Project : A Case Study Review from Pakistan ». Applied Sciences 11, n^o 4 (12 février 2021) : 1655. http://dx.doi.org/10.3390/app11041655.

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During underground construction, the behavior of the ground is influenced by characteristics of the rock mass with situ stresses and ground water, cross section of the excavation area, excavation method, and the rate of excavation. These fundamental features are considered to ensure the support and stability of underground excavations and achieve long-term successful operation. However, the ground composition of the Himalayas hinders tunnel excavation, especially in case of mechanized tunneling; this causes time and cost overruns. This study has reviewed the recently completed Neelum–Jhelum Hydroelectric Project; the project complexities, geological environments involving significant overburden and tectonic stresses, and effects of the excavation method on tunnel stability were analyzed. The major challenges that were encountered during construction are discussed herein along with their countermeasures. An analysis of project-related data reveals that latest techniques and approaches considering rock mechanics were used to complete the project; the existing approaches and methods were accordingly verified and extended. Apart from ground composition, the excavation methods used play an important role in the occurrence of severe rock bursts. Thus, the findings of this study are expected to be helpful for future tunneling projects in the Himalayas.

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Guo, Jian, Guobin Liu et Lei Xu. « Numerical analysis of the surrounding responses induced by an irregular excavation in soft soil ». IOP Conference Series : Earth and Environmental Science 1336, n^o 1 (1 mai 2024) : 012028. http://dx.doi.org/10.1088/1755-1315/1336/1/012028.

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Abstract This study focuses on an “X”-shaped irregular excavation in Shanghai, presenting a detailed numerical analysis of the impact of the excavation on the surrounding area and the deflection of the retaining wall. By comparing computational outcomes with onsite observations, the research delves into the interaction between the excavation process and pre-existing underground structures within soft clay environments. The present findings reveal that proximate subsurface structures can mitigate retaining wall deflection and ground settlement by up to 30% within a distance ranging from 0.65 He to 1.0 He (He denotes the excavation depth). Furthermore, the intersection angle between the excavation site and the existing underground infrastructure significantly affects the excavation’s dynamics. Within areas influenced by these underground structures, the observed retaining wall deflection and ground subsidence were approximately 15-20% less compared to regions without such constraints.

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Xu, Changjie, Yuanlei Xu, Honglei Sun et Qizhi Chen. « Characteristics of Braced Excavation under Asymmetrical Loads ». Mathematical Problems in Engineering 2013 (2013) : 1–12. http://dx.doi.org/10.1155/2013/452534.

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Numerous excavation practices have shown that large discrepancies exist between field monitoring data and calculated results when the conventional symmetry-plane method (with half-width) is used to design the retaining structure under asymmetrical loads. To examine the characteristics of a retaining structure under asymmetrical loads, we use the finite element method (FEM) to simulate the excavation process under four different groups of asymmetrical loads and create an integrated model to tackle this problem. The effects of strut stiffness and wall length are also investigated. The results of numerical analysis clearly imply that the deformation and bending moment of diaphragm walls are distinct on different sides, indicating the need for different rebar arrangements when the excavation is subjected to asymmetrical loads. This study provides a practical approach to designing excavations under asymmetrical loads. We analyze and compare the monitoring and calculation data at different excavation stages and find some general trends. Several guidelines on excavation design under asymmetrical loads are drawn.

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V, Musiiko, Koval A et Patsora D. « WAYS TO INCREASE THE PRODUCTIVITY IN CONTINUOUSLY OPERATING TRENCHING EXCAVATORS ». National Transport University Bulletin 1, n^o 50 (2021) : 132–43. http://dx.doi.org/10.33744/2308-6645-2021-3-50-132-143.

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The article considers and reasons the ways and possibilities to create the highly efficient constructions of trenching excavators that dig trenches of the defined profile by means of using bucketless rotors as soil excavating implements together with design of the discharge assembly improved construction. Study objective: to create a bucketless highly efficient rotary implement of the trenching excavator with two-stage discharge. Study object: continuously operation earthmoving machines. Research technique – analytical-experimental. One of the most important problems for the machine-building industry of Ukraine is the efficiency improvement of machines created in the country. Solving of this problem is required due to necessity to perform the increasing amount of earthworks in building and construction works. The cheapest way to perform lengthy soil excavations is to excavate them with trenching excavators. Increasing of their productivity is the one of the main directions to improve the efficiency of the earthworks mechanization. Increasing the efficiency of trenching excavators is possible by means bucketless rotary implement usage and by improving of the rotary discharge process. The study justifies and proves the scientific hypothesis about the possibility to use the force of the soil flow header pressure create by the soil that is being transported from the excavation for the bucketless rotary implements discharge. This allows by means of two-stage discharge of the implement to ensure the full clean-up and to improve the productivity of the soil excavation. The study analytically justifies the requirements for the main construction parameters of the bucketless rotor. Based on the obtained results the technical proposal is created for highly efficient construction of the bucketless rotary implement of the trenching excavator with two-stage discharge. KEYWORDS: BUCKETLESS ROTOR, SOIL, TWO-STAGE, DISCHARGE, DISCHARGE ASSEMBLY, TRENCH DIGGER

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Zhang, Liwei, Weiguo Zhang, Zaiquan Wang, Sijia Liu et Kai Liu. « Instability Risk Assessment for Deep Excavation of Soil–Rock Combinations Containing Groundwater ». Applied Sciences 13, n^o 23 (30 novembre 2023) : 12887. http://dx.doi.org/10.3390/app132312887.

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Dynamic risk assessment is a pivotal tool for enhancing construction safety and minimizing the potential for partial failure during deep and extensive excavation projects. To enhance the efficacy of dynamic risk assessment in deep excavation, this study introduces a novel risk assessment model designed to evaluate instability risk in extensive excavations. It comprises a risk factor selection model for identifying the most pertinent factors and an instability risk assessment model for gauging the extent of instability risk throughout the construction process. Then, the model was deployed in the construction of Anshan Road Station of the Qingdao Metro. To pinpoint the factors with the most pronounced impact on excavation instability, a risk factor selection model was employed, yielding a comprehensive risk evaluation index system. For real-time assessment of risk, the monitoring data were used as the primary source of evidence. A comprehensive comparative analysis involving actual data and predictions from conventional RBF and back propagation neural networks was performed. The outcome of this analysis underscored the superior accuracy and predictive capabilities of the assessment model. The instability risk assessment model offers the ability to dynamically evaluate the instability risk associated with extensive excavations featuring a combination of soil and rock. It can serve as a valuable methodological tool, furnishing essential support for the systematic prevention and mitigation of excavation instability disasters.

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Liu, Chuancheng, Xikui Sun, Xiufeng Zhang, Qiangyong Zhang et Yang Chen. « A Geomechanical Model Test on the Construction Stability and Overload Failure Process of an X-Type Cross Cavern Group ». Shock and Vibration 2023 (25 juillet 2023) : 1–16. http://dx.doi.org/10.1155/2023/5864013.

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The geological environment of the surrounding rock in deep underground engineering will become more and more complex, along with the excavation depth continuously increasing. Under these conditions of high temperatures, high seepage, high geostress, and strong excavation disturbance, the surrounding rock during underground engineering can experience obvious nonlinear deformation failure. In order to guarantee the construction, excavation, and operational safety of deep underground engineering, we have to comprehensively study the failure characteristics and deformation characteristics of the surrounding rocks of the cavern. To reveal the interaction between structures and the characteristics of overloading-induced damage and safety factor, a geomechanical model test of an X-type cross cavern group was carried out during the excavation process and overloading process. The engineering background is the URL of HLW for the geological disposal in Beishan. This is the first time that this type of geomechanical model test is being carried out. The law of displacement and stress change during the process of excavation and the law of deformation and the failure of surrounding rock in the process of overload are obtained. The test results show that the stress and displacement changes at the intersection of the caverns are most significant after excavation. The excavation’s impact range is approximately 1.5 to 2 times the tunnel diameter. Under these test conditions, the safety coefficient of the crack initiation is 2.1, the safety coefficient of the local destruction is 2.5, and the safety coefficient of the general demolition is 2.9. These test results provide technical support for the design and construction of an URL for the deep buried geological disposal of HLW and have important practical significance.

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Li, Bo, Cangqin Jia, Guihe Wang, Jun Ren, Gaofeng Lu et Nannan Liu. « Numerical Analysis on the Performance of the Underwater Excavation ». Advances in Civil Engineering 2020 (9 novembre 2020) : 1–14. http://dx.doi.org/10.1155/2020/8894138.

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Based on the Yongdingmen Station of Beijing Metro, the underwater excavation method for deep foundation pit was introduced. This study constructed a numerical analysis model to analyze the performance of surface settlement and lateral wall deflection in the process of underwater excavation. Results showed that this method was better to control the surface settlement and lateral wall deflection compared with other dewatering excavations. In detail, most of the surface settlement was caused during the dry excavation stage and dewatering excavation stage while the deflection caused by underwater excavation only accounted for about 10% of the total settlement. Besides, the maximum settlement occurred 0.25∼0.5 H e behind the retaining wall and the value was 0.04% H e . Similar to the result of the surface settlement, most of the lateral wall deflection had been completed before the underwater excavation, which only caused about 7% of the total deflection. The maximum wall deflection and its location were approximately 0.06% H e and 0.5 H e , respectively. Moreover, a series of 3D numerical analyses were studied on the design parameters of the underwater excavation method. This study can be used as a reference for general performance and structural design of foundation pits with underwater excavation.

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Popescu, Florin Dumitru, Sorin Mihai Radu, Krzysztof Kotwica, Andrei Andraș, Ildiko Kertesz Brînaș et Stela Dinescu. « Vibration analysis of a bucket wheel excavator boom using rayleigh’s damping model ». New Trends in Production Engineering 2, n^o 1 (1 octobre 2019) : 233–41. http://dx.doi.org/10.2478/ntpe-2019-0024.

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Abstract For the ERc 1400-30/7 type bucket wheel excavator (BWE) used in various Romanian open pit mines, a virtual model of the boom was constructed in SolidWorks. On this model, the variable in time forces acting during the excavation process were simulated, and the time history analysis (time response) was performed. This dynamic time response analysis was performed for excavation of homogenous material only, considering the damping as being of Rayleigh’s type, where the damping matrix is a linear combination of the mass and stiffness matrices. Based on the conducted analysis, the displacements of the boom during excavation were observed.

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Ermakov, Valentin A., et Ekaterina I. Belova. « Technological solutions for excavation works in the process of implementation of the “top-down” approach ». Stroitel'stvo : nauka i obrazovanie [Construction : Science and Education] 12, n^o 4 (30 décembre 2022) : 23–32. http://dx.doi.org/10.22227/2305-5502.2022.4.2.

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Introduction. Underground space development in the course of infill construction in confined spaces of megalopolises is a promising development trend in construction. To save the workspace, the “top-down” approach can be used. In this case, a substantial portion of the underground work consists in the soil development and loosening under the protection of beams, which is relevant for frozen soils in Central Russia. The analysis of regulatory documents and the studies, conducted in this area, has proven that there are no methodological recommendations on the arrangement of soil excavation in confined spaces. The purpose of the study is to analyze and systematize current methods of soil development and loosening and to evaluate their applicability in confined spaces. Materials and methods. The authors consider widely used excavation techniques (mechanical, hydro-mechanical, and explosive ones) and less widely spread soil development methods (electric pulse and thermal ones). The expediency of excavation mini-technologies, designed for works in confined spaces, is emphasized. Attachable hydraulic and electromagnetic machinery, used to loosen soils, is analyzed. The analysis of these methods shows their strengths and weaknesses, as well as the applicability of the “top-down” technique. Results. Combinations of machines designated for soil excavation and loosening within the framework of the “top-down” technique are made to further estimate the engineering and economic performance and their comparative analysis. The authors propose combinations of excavating machines that represent lightweight or mini-items having mounted soil loosening and excavation mini-machines. Conclusions. The practical value of the study consists in the analysis of available methods of soil excavation and loosening and the assessment of their applicability to the confined conditions of construction of substructures of buildings using the top-down technology, which is relevant for Central Russia. The authors made combinations of machines whose operation is mostly based on mechanical methods. The authors suggest considering the use of mini-machines and attachments.

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Huang, Jie, Zeping Yang et Qinyue Lin. « Experimental Investigation on Deformation Characteristics of Strutted U-Shape Sheet Pile Flexible Retaining Structures in Excavations Using 3D Printing ». Applied Sciences 13, n^o 14 (13 juillet 2023) : 8163. http://dx.doi.org/10.3390/app13148163.

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U-shape steel sheet piles are widely used in deep and large excavation engineering due to their excellent soil-retaining and water-stopping performances. To achieve deformation control in excavations, an experimental investigation on the deformation characteristics of a strutted U-shape sheet pile flexible retaining structure was conducted. Single-layer and double-layer strutted retaining structure excavation indoor model tests in sand, where U-shape sheet piles were formed by 3D printing, were successfully accomplished. Deformation was monitored in real time during the test. The results show that the lateral displacement mode of the retaining structure transformed with the change in excavation from the “cantilever” to the “bulge” and finally developed into an intricate “recurve bow”. The average maximum lateral displacement was 0.756% of the excavation depth. With a maximum settlement of 0.375% of the excavation depth on average, the distribution of ground settlement behind walls changed from “exponential” to “triangular” before ultimately transforming into “trough” or “trapezoid” mode. The maximum settlement to maximum lateral displacement ratio (smax/δmax) on average was 0.54; the maximum settlement deformation rate was always less than the maximum lateral displacement deformation rate.

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Lukashuk, Olga, Konstantin Letnev et Anatoliy Komissarov. « Efficiency increase in excavation control as primary reserve of performance increase for open-pit excavators ». MATEC Web of Conferences 224 (2018) : 02028. http://dx.doi.org/10.1051/matecconf/201822402028.

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It is shown that controlling excavation of rock mass using an open-pit excavator with a front shovel as its operational equipment is quite a difficult task due to the complexity of control under almost nonstop adjustment of velocities of working motions (hoisting and thrusting). It was established that operation parameters of the main mechanisms depend on the type of path of motion and position of the bucket in the excavator’s work area. The process of excavation was algorithmically described, and kinematic transfer functions for the operational equipment mechanism were determined, characterizing correlations between the velocity of excavation and the velocities of working motions.

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Zhang, Jiao. « Analytical Hierarchy Process Applied to Risk Analysis of Deep Excavation ». Advanced Materials Research 250-253 (mai 2011) : 1646–50. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.1646.

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The application of the analytical hierarchy process (AHP) to the risk analysis of deep excavation was investigated. Firstly, the occurring probabilities of various risk factors during deep excavation were calculated. Secondly, the aftereffects of the risks were concluded by consulting the experts. Thirdly, the weight of each risk factor was obtained by AHP. Finally, the total risk of deep excavation could be evaluated by fuzzy complex evaluation. This risk analysis method was applied to evaluate the total risk of a real deep excavation, and the exemplification verified its feasibility.

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Lee, Yu-Lin, Wen-Kuei Hsu, Pei-Wen Hsieh, Chi-Huang Ma, Ming-Yi Lin et Chi-Min Lee. « Mechanical Behavior Analysis of Excavation and Retaining Piles in Gravel Formation along Adjacent Railways : A Comparative 3D FEM Study with Monitoring Data ». Applied Sciences 13, n^o 1 (28 décembre 2022) : 397. http://dx.doi.org/10.3390/app13010397.

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Carrying out underground excavation work with retaining pile supports adjacent to a running railway is a risky and cautious job. To evaluate the safety and practicability of underground excavation, a three-dimensional finite element program was developed and used in this study to simulate and analyze the mechanical behavior of the gravel layer in response to excavation to serve as the design for retaining piles as supports. Monitoring instruments (such as inclinometers and subsidence observation points on railway track surfaces) were installed during construction to provide immediate monitoring of the excavation area and information for safety assessments. The calculation process in the numerical analysis included the execution of programs such as pre-processing, central calculation, and post-processing, as well as the simulation of construction steps, such as the initial stress of gravel layer, railway vehicle load, layered excavation, and support installation. By comparing the results of 3D finite element analysis with monitoring data, it was found that the construction method of excavating the gravel layer near the adjacent railway and supporting it with retaining piles provides a reliable engineering technology. The results of the comparative analysis were all within a safe range and showed a consistent trend.

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Zhang, Xue Fu, et Jia Xiang Liu. « Study on Excavation Method of Tunnel with Super Cross-Section and Super Large Section Area Underpass Extra-High Building ». Advanced Materials Research 250-253 (mai 2011) : 2057–67. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.2057.

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Because double side drift excavation method named eye excavation method has been a mature and reliable excavation method, it has normally been used in tunnels with super cross-section and super large section area. However, the construction speed using this method is very slow. One of reasons is that the construction technology of this method would be more and complex. The other is that all construction workers, materials, equipment would be extremely difficult for their up and down, and that the ballast rock would have to be moved by artificial when the upper step of the middle guide hole would be excavated. In this paper, to speed up the process of excavating tunnel with super cross-section and super large section area underpass extra-high building, the elastic-plastic numerical simulations for the tunnel named Industry and Trade Station of the third line in Chongqing Rail Transit were made in four excavation methods conditions. The four excavation methods is respectively the double side drift excavation method to the first excavation in main building side, the double side drift excavation method to the first excavation in podium side, the single side drift excavation method in the upper step to the first excavation in main building side and the single side drift excavation method in the upper step to the first excavation in podium side. The main building is named Industry and Trade building with 22 floors. The results showed that the single side drift excavation method in the upper step could Insure the building and tunnel when the support measures were reasonable, that the guide hole beside the little surface load should firstly be excavated by whether double side drift excavation method or single side drift excavation method, and that these would provide a reference for some similar engineering.

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Zheng, Yuchao, Jianyong Lei, Fei Wang, Liang Xiang, Jianfeng Yang et Qingshuai Xue. « Investigation on Dewatering of a Deep Shaft in Strong Permeable Sandy Pebble Strata on the Bank of the Yellow River ». Geofluids 2021 (24 septembre 2021) : 1–15. http://dx.doi.org/10.1155/2021/9994477.

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This paper reports the dewatering scheme of a deep excavation in sandy pebble strata. The excavation is in high permeability strata and is close to the Yellow River, making the dewatering difficult during construction. At present, few researchers have specially studied the dewatering scheme of deep excavations in strong permeable strata near the water resource. Field pumping test was conducted before the excavation activity, and the permeability coefficient of the strata was obtained by reverse analysis. According to the characteristics of the project, the dewatering scheme of “ waterproof curtain + base grouting + pumping ” was proposed. The influence of vertical waterproof curtain and base grouting on dewatering was analyzed by numerical simulation. In the construction process, the field water table and ground settlement were measured. The results show that (1) the groundwater table versus permeability coefficient curve shows three different stages and (2) the dewatering scheme of “ waterproof curtain + base grouting + pumping ” is effective for deep excavation in strong permeable strata.

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Liu, Zhen, Cui Ying Zhou, Heng Chen et Li Guo Dong. « 3D Visualization Technology for the Influence on the Surrounding Environment Caused by Excavation ». Advanced Materials Research 243-249 (mai 2011) : 3098–104. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.3098.

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On the basis of visualization of 3D stratum, deep excavation simulation is accomplished by combining with numerical analytical method, Excavation effect on surrounding environment is analyzed. By using experimental or semi-experimental models, the settlement values and their distribution features, which are caused by excavation, are discussed, by using 3D FEM, the horizontal displacement of excavated foundation ditch is calculated, and the OpenGL technology and triangle split arithmetic are chosen to implement the construction and splitting of 3D strata, the excavating process and its influence on the surrounding environment are ultimately realized. By comparing with engineering cases, the validity of analysis model and implement method are shown to be correct, feasible, and efficient.

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Raimzhanov, B. R., A. R. Khasanov et R. R. Vakhitov. « The Study of Parameters of Quarry Faces in Muruntau and Myutenbai Open Pits in Case of Applying Major Blasts ». Mining science and technology 4, n^o 1 (27 avril 2019) : 4–15. http://dx.doi.org/10.17073/2500-0632-2019-1-4-15.

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The paper presents process layouts for excavation of zones near pit envelope based on the analysis of findings of the ore loss study in case of open-pit mining, as well as the results of field measurements in the quarry faces in Muruntau and Myutenbai open pits. In the course of the field measurements, parameters of the quarry faces at Muruntau and Myutenbai open pits were determined under the following working conditions of an excavator: at full bench with shotpile height of 19–21 m; at full bench with shotpile height of 12–14 m at excavation of the “blast cap”; at heading face and taking ramp material. In all the above-listed quarry faces, the slope angles and the ore mass shotpile height when excavating were measured. Besides, the used excavator type (dragline or hydraulic) was taken into account. For each face, 2–3 measurements were performed, and the average slope angle at the ore mass excavation was determined for each type of excavator. At the next stage of the field measurements, the bench height in the rock mass and the shotpile parameters were measured before and after blasting operations under the following arrangements for preparing the rock mass for excavation: a) under normal conditions, when the ore mass blasting is performed for the selected face or relieving wall of the required thickness; b) in compression with a “blast cap” formation; c) in the marginal parts of the bench. Based on the results of the actual bench height and the blasted rock shotpile parameter field measurements, the following conclusions were drawn: a) the actual slope angles of the quarry faces were 49° when excavating the “blast cap” using dragline excavators, and 53° when excavating the ore mass at full bench regardless of the excavator type used; the slope angles of 49° for the dragline excavator and 53° for the hydraulic excavators were taken for further calculations; b) the width of the marginal (near-envelope) zone, where losses and dilution of balance ore are generated, increased from 7 to 13.0 m (at 49°) and from 7 to 11.3 m (at 53°); as a result, the areas of loss and dilution triangles have increased; c) when blasting in compression conditions, in the upper part of the shotpile, intense mixing of the involved rock and all ore grades occurs, therefore, when excavating the “blast cap”, bulk ore mass mining is only possible. The lower part of the blasted bench preserves the geological structure of the rock mass to a greater degree and can be selectively excavated with separation of the ore mass by grade; d) when blasting the rock mass, to maintain the required pulse direction and the blasting sequence, barren boreholes are included in the breaking outline, which increase the balance ore dilution, and structural dilution arises, which should be taken into account when drawing up the "Methods for determining, limitation and accounting for ore losses and dilution in the course of the Muruntau and Myutenbai (the fifth stage) open-pit mining"; e) when compiling the "Methods ...", the option of dividing a bench of 15 m high into two sub-benches of 7.5 m should be considered.

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Chen, Shangrong, Jifei Cui et Fayun Liang. « Case Study on the Deformation Coupling Effect of a Deep Foundation Pit Group in a Coastal Soft Soil Area ». Applied Sciences 12, n^o 12 (18 juin 2022) : 6205. http://dx.doi.org/10.3390/app12126205.

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Simultaneous construction of adjacent projects may lead to emergencies in a foundation pit group, which significantly affects the deformation and safety of foundation pits. In this study, the deformation characteristics of a deep foundation pit group and the mutual interactions among the adjacent foundation pits were observed by a monitoring system during excavation. Field data of the foundation pit group, including the lateral deflections of the enclosure pile, the ground subsidence, as well as the vertical column movements, were analyzed and compared with individual excavations in Shanghai. The field data showed that the excavation of the adjacent foundation pit reduced the lateral deformation of the enclosure structure, caused by the reduction of active earth pressure acting on the retaining pile. Furthermore, the foundation pit excavated later caused upward movements of the soil between them. However, the foundation pit excavated earlier had a negligible influence on the vertical column movements of the foundation pit excavated later. Due to the optimized excavation sequence of the deep foundation pit group, the deformation of this special excavation was well controlled.

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Musiiko, Volodymyr, Andrii Koval, Yuri Lazaruk et Yuri Pasenko. « INCREASING THE EFFICIENCY AND EXPANDING THE TECHNOLOGICAL CAPABILITIES OF THE UNIVERSAL EARTH-MOVING MACHINERY BY IMPROVING THE KINEMATICS OF THE MOVEMENT OF THEIR OPERATING ELEMENT IN THE SOIL ». Automobile Roads and Road Construction, n^o 114.2 (2023) : 230–44. http://dx.doi.org/10.33744/0365-8171-2023-114.2-230-244.

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This article addresses the creation and optimization of designs for Universal Continuous-Action Earthmoving Machines (UCAEM) capable of excavating extensive trenches of various widths, depths, and shapes without structural changes to the operating equipment. The paper provides a detailed rationale for the relevance and practical feasibility of developing continuous-action universal earthmoving machines. Analytically, the required trajectory of movement for the soil excavation operating element of UCAEM in the process of constructing wide trenches (excavations) in the soil is determined. This trajectory resembles a Bernoulli lemniscate, along which the operating element of UCAEM moves to excavate the soil in evenly thick planar chips. This enables the construction of trenches in the soil with maximum work productivity, minimizing external loads on the earthmoving machine's operating element. To implement the above, a physical model of the rotary operating equipment of UCAEM was created, and experimental studies were conducted. The design of the UCAEM operating element movement drive is based on a two-circuit lever mechanism with fifth-class rotary pairs, providing the delivery of the soil-excavating operating element to the soil face. Soil excavation is carried out in the mode of fan-linear feed of the operating element to the face. The movement of the operating element in the face is performed by a lever mechanism with three degrees of freedom, each link of the mechanism is provided with an individual turning drive using a pair of hydraulic cylinders relative to the hinge of its attachment. An algorithm for the operation of the drive for the movement to the face of the two-circuit soil-excavating rotary operating equipment of continuous-action UCAEM has been synthesized, providing soil excavation with chips of uniform thickness in plan, regardless of the width of the trench, and consequently, increasing the productivity of the machine's operation. Equalization of the chip thickness in plan is achieved by turning the intermediate frame of the operating element at the end of each half-cycle of the working process. An algorithm for the movement of the operating element during the construction of entry and exit ramps during the construction of trenches in the soil over several passes of the operating element has been justified.

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Xiao, Zun-Qun, Jian Lin et Dong-Sang Tang. « A Numerical Study of Ground Displacement and Stress Conditions of Small and Medium Circular Diaphragm Wall during Excavation ». Advances in Civil Engineering 2022 (19 juin 2022) : 1–22. http://dx.doi.org/10.1155/2022/8116804.

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In the present study, a dimensional total-stress elasto-plastic FEM analysis was conducted, which was based on the Mohr-Coulomb constitutive model. The model was combined with a practical engineering case in order to investigate ground displacements and stress conditions during the installations of a medium-sized and a small-sized circular diaphragm wall, as well as the subsequent soil excavations within the walls. The distribution characteristics of the lateral radial displacements and stress conditions in the ground following the wall installations and excavations within the walls were investigated. Also, two different excavation methods, as well as three different soil depths for the walls, were considered. The distributions of the internal forces along the depth directions of the radial sections of the walls were also analyzed in this study. The analysis results showed that the slotting order had made the model nonaxisymmetric, which had further influenced the distribution characteristics of radial stress and displacements. It was found that the distributions of the horizontal radial displacements, along with the stress levels of the soil behind the walls, were only minimally affected by the excavations of the soil in the shaft. The internal force distribution of the wall radial section caused by the direct excavation method and the reverse excavation method is very small, that is, the wall bending moment generated by the reverse excavation process is larger, and the most obvious near the rock-socketed depth. The distribution pattern of the bending moment depth corresponding to different excavation construction methods is similar. Furthermore, the soil penetration depths of the walls were determined to have had little influence on the internal force distributions of the radial sections of the walls above the foundation pit. However, there was a greater influence observed on the internal force distributions of the radial sections of the walls below the foundation pit.

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Mei, Yuan, Lu Wang, Dongbo Zhou et Liaoyuan Fu. « Displacement Characteristics of a Deep Excavation in Hangzhou Soft Clay ». Advances in Civil Engineering 2022 (16 mars 2022) : 1–16. http://dx.doi.org/10.1155/2022/5469471.

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Excavations in a soft soil area are usually associated with substantial difficulties. Taking a special-shaped deep foundation pit in Hangzhou soft clay as the research object, the excavation performances, including groundwater level height, axial force, lateral wall, and soil deflection, and ground surface settlement were monitored and summarized based on the data published in the literature on similar excavations in Hangzhou, P. R. China. The following conclusions are drawn: (1) The axial forces of the struts dynamically change during the excavation and construction or removal of adjacent braces. (2) The ratio between the measured maximum wall deflection and excavation depth δ h − max / H e is 0.14–0.17%, larger than those in Shanghai. (3) The surface settlement behind the wall has an obvious primary influence zone and secondary influence zone, characterized by a “groove shape” and “triangle shape,” respectively. The maximum ground surface settlement δ v − max ranges from 0.29% to 0.5% of the excavation depth. (4) The distribution of the ground settlement was analyzed. The relationship between the maximum settlements δ v − max is between 1.28 δ h − max and 3.72 δ h − max . Moreover, ABAQUS software with Mohr–Coulomb soil models was used for model analysis of the construction process. The research results have important significance for the effective prevention of foundation pit accidents and the optimal design of deep foundation pit projects.

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She, Fang Tao, Sheng Jun Shao, Juan Fang et Yang Yang Jiao. « Calculation Model for Ground Settlement Process of Xi’an Subway Tunnel Non-Synchronous Excavation with Double-Line ». Applied Mechanics and Materials 90-93 (septembre 2011) : 2221–25. http://dx.doi.org/10.4028/www.scientific.net/amm.90-93.2221.

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The current calculation models of ground settlement for tunnel excavation cannot reflect ground settlement of tunnel non-synchronous excavation with double-line. Based on the Peck ground settlement formula and Attewell ground settlement formula, displacement release of excavation place and tunnel non-synchronous excavation with double-line have researched. By means of finding a function to replace the accumulated probability curve, the new control function was beneficial to parameter introduced and improvement of the current ground settlement formula. By introducing the non-synchronous excavation distance and the displacement release coefficient of excavation place, A new calculation model for ground settlement process of tunnels non-synchronous excavation with double-line is proposed. The reliability and practical of the calculation models was verified. Research results were very important to analyze the ground settlement affecting the building foundation and pipe under ground.

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Li, Tingting, Min Yang et Xiaocen Chen. « Lateral Deformation Response of an Adjacent Passive Pile under the Combined Action of Surcharge Loading and Foundation Excavation ». Sustainability 15, n^o 18 (12 septembre 2023) : 13619. http://dx.doi.org/10.3390/su151813619.

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With the increasing development of civil engineering in large cities, more and more excavations and surcharge loadings are being constructed or planned adjacent to existing building piles in crowded urban areas. Previous study on pile deformation has primarily focused on surcharge loading or foundation excavation and given little concern to the combined action of surcharge loading and foundation excavation. The article develops a two-stage process to assess the lateral displacement of nearby pile foundations induced by the combined action of surcharge loading and excavation. Firstly, the local plastic deformation theory and Boussinesq solution are used to accurately predict the passive loading of adjacent pile foundations caused by surcharge loading; Mindlin formulas are adopted to predict the passive pile’s additional lateral stress applied by excavation. Secondly, Pasternak models are adopted and the finite difference method is used to establish the deflection differential formula of the single passive pile. Last but not least, a parametric study is conducted to investigate the influence of the loading dimensions, loading magnitudes, and three-dimensional excavation dimensions. The findings of the calculations reveal that the loading magnitudes have a more significant impact on the lateral displacement of the pile compared to the loading dimensions. Therefore, a concentrated surcharge loading should be avoided. Additionally, the excavation depth has a greater influence on the lateral displacement of the pile compared to the excavation area. In order to mitigate this situation, a step excavation should be implemented for each layer of soil, with the soil excavated away from the pile foundation first.

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Kostić, Srđan, Milan Stojković, Velibor Ilić et Jelena Trivan. « Deep Neural Network Model for Determination of Coal Cutting Resistance and Performance of Bucket-Wheel Excavator Based on the Environmental Properties and Excavation Parameters ». Processes 11, n^o 11 (26 octobre 2023) : 3067. http://dx.doi.org/10.3390/pr11113067.

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In the present paper, we develop a new model, based on the implementation of deep neural networks, for the estimation of a series of excavation parameters, depending on the main environmental and excavation properties. The developed model, with high statistical accuracy (R > 0.79) and small RMSE (<17% of the actual output values), enables the simultaneous assessment of the following excavation parameters: effective capacity Qef, maximum current consumption Imax, maximum power consumption Nmax, maximum force consumption Pmax, maximum energy consumption Emax, and maximum linear and areal cutting resistance, KLmax and KFmax, respectively, based on the impact of the following environmental properties and excavation parameters: coal unit weight, coal compression strength, coal cohesion, friction angle, excavator movement angle in the left and right direction, slice height and thickness, and wheel velocity. The data analyzed in the present paper were previously collected from three neighboring open-pit coal mines in Serbia: Tamnava Western Field, Tamnava Eastern Field, and Field D. These mines have similar geological conditions and coal properties. Additionally, for each output factor, a complex analysis is provided on the impact of the examined input factors, by applying the multiple linear regression method. As far as we are aware, this is the first time such a comprehensive estimation model has been suggested for the operation of a bucket-wheel excavator in the Neogene coal basins. The deep neural network (DNN) model, trained over 300 epochs, shows an MSE range of 6.7–16.5% across various input factors, with distinct evaluations for Imax due to its unique values (4.8–12.5%).

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Cho, Hanpil. « Review of excavation process about Yu Gwansun ». Paek-San Society 113 (30 mars 2019) : 53–80. http://dx.doi.org/10.52557/tpsh.2019.113.53.

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Ruan, Yanmei, Xu Luo, Jin Li, Yang Li, Shan Lin, Chengkun Ling et Bingxiang Yuan. « Deformation Law of Tunnels Using Double-Sidewall Guide Pit Method under Different Excavation Sequences ». Applied Sciences 13, n^o 23 (28 novembre 2023) : 12764. http://dx.doi.org/10.3390/app132312764.

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The double-sidewall guide pit method finds extensive application in the construction of large cross-section tunnels in soft rock strata due to its minimal disruption to the surrounding rock, thereby enhancing tunnel stability. To investigate the loading and deformation patterns of the surrounding rock and tunnel support using the double-sidewall guide pit method, this study compares the impacts of various construction sequences on surface settlement, surrounding rock stress, and lining stress using indoor model tests. The experimental results show that after excavating the upper guide hole on one side, the excavation of the lower guide hole on the same side is carried out. The upper and lower support structures form a closed loop, and the structure can better constrain the surrounding rock and control the deformation of the surrounding rock, whereas the lower structure can share the stresses suffered by the upper structure. Therefore, compared with the upper and lower excavation methods, the surface settlement caused by the left and right excavation methods is smaller, the disturbance to the surrounding rock is smaller, and the supporting structure is more evenly and stably stressed in the excavation process.

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Yasrebi, Shahab, et Emad Zolqadr. « Numerical modelling for optimizing shoring wall performance in deep urban excavations ». IOP Conference Series : Earth and Environmental Science 1336, n^o 1 (1 mai 2024) : 012004. http://dx.doi.org/10.1088/1755-1315/1336/1/012004.

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Abstract Soil nailing and anchoring are effective methods for reinforcing the soil in situ, providing internal support that enables the earth to sustain itself during and after excavation. To ensure optimal performance, it is essential to monitor the behavior of the soil nail walls throughout the excavation and after completion, so that the SOE system design can be improved. This study presents a comprehensive survey of the design and performance of soil nail walls in deep urban excavations at depths ranging from 19.5 to 29.3 m. After construction, the lateral deformations of the soil nail walls varied significantly from 69% to 222% of the initial deformations observed immediately after completion. Numerical analyses were used in the design process to accurately predict the wall performance and determine the design characteristics to identify appropriate design parameters and predict the wall behavior. Several numerical models using different modelling approaches are examined, and the results demonstrated that post-construction deformation rates can vary between walls based on factors such as the soil nail and anchor system design and geotechnical conditions at the excavation site. A thorough understanding of these variables is crucial for optimizing the performance of SOE systems in deep urban excavations.

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Shan, Bao Xue, Lu Chao Liu et Cui Wei. « Numerical Simulation Research on the Mechanical Process of Pile-Anchor Retaining Deep Building Foundation Pit ». Applied Mechanics and Materials 353-356 (août 2013) : 421–25. http://dx.doi.org/10.4028/www.scientific.net/amm.353-356.421.

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In this paper, based on an actual pit excavation project, the mechanical process of excavating and retaining is simulated. Combined with the monitoring data, the stress, displacement of soil and internal force of retaining structures are analyzed, and the characteristics of deformation and force are summarized. This research offers references for safe and economical design and construction, and helps to improve the design theory of foundation pit support.

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Trainor, Conor P. « THE LATE HELLENISTIC WINE PRESS EXCAVATIONS FROM KNOSSOS : THE EARLY IRON AGE, HELLENISTIC AND EARLY ROMAN CONTEXTS ». Annual of the British School at Athens 116 (6 octobre 2021) : 235–90. http://dx.doi.org/10.1017/s0068245421000095.

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The remains of an exceptionally well-preserved Hellenistic wine press were uncovered during a rescue excavation at Knossos in 1977. The architecture, stratigraphy and faunal remains from this campaign were published in BSA 89 (1994) by J. Carington Smith (the excavator) and S. Wall. The artefact assemblages from this excavation, however, have remained unstudied and unpublished until now. The current article presents the artefact assemblages from the wine press excavation and considers them within their urban context at Knossos. The key findings from this excavation relate to the Late Hellenistic wine press and its associated material, which enables us to consider both the ancient winemaking process at Knossos and the economic topography of the city in the decades around the Roman conquest of the island in 67 bc. In addition to the Late Hellenistic phase, material of Minoan, Early Iron Age–Early Archaic, earlier Hellenistic and Early Roman dates is also presented and discussed.

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Rotisciani, G. M., S. Miliziano et S. Sacconi. « Design, construction, and monitoring of a building with deep basements in Rome ». Canadian Geotechnical Journal 53, n^o 2 (février 2016) : 210–24. http://dx.doi.org/10.1139/cgj-2015-0244.

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In this paper, excavations for the construction of a tall building with deep basements in a congested area in Rome, close to the Tiber river are described. The project was technically challenging due to the close proximity of existing buildings, the interaction with the river, and the poor geotechnical properties of the alluvial deposits. This well-documented case study addresses the geotechnical and structural issues involved in the development of the design and construction process. Particular attention is focused on the prediction of excavation-induced displacements and on the efficiency of the water wells introduced to increase safety margins against the hydraulic uplift of the excavation bottom.

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