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Full-Text Articles in Geotechnical Engineering
Characteristics And Mechanism Of Soil Heave At The Bottom Of Ultra-Deep Circular Shafts In Soft Soil Areas, Ya-Fei Qiao, Kai Yan, Teng-Teng Zhao, Wen-Qi Ding
Characteristics And Mechanism Of Soil Heave At The Bottom Of Ultra-Deep Circular Shafts In Soft Soil Areas, Ya-Fei Qiao, Kai Yan, Teng-Teng Zhao, Wen-Qi Ding
Rock and Soil Mechanics
Based on an ultra-deep circular shaft project in Shanghai, the field data of soil heave at the bottom of the pit during the construction were collected, and the vertical distribution pattern, evolution law and main influencing factors of soil heave at the bottom of the pit were summarized. An axisymmetric numerical model was then built and verified to investigate the effect of the excavation-induced unloading, dewatering, diaphragm wall and soil mechanical properties on the soil heave, then the mechanism of soil heave was revealed. Soil heave was the combined result of the soil mechanical response under the excavation-induced unloading, dewatering, …
Mechanism Of Liquefaction-Induced Lateral Spreading In Liquefiable Inclined Sites, Ke-Min Jia, Cheng-Shun Xu, Xiu-Li Du, Xiao-Ling Zhang, Jia Song, Zhuo-Lin Su
Mechanism Of Liquefaction-Induced Lateral Spreading In Liquefiable Inclined Sites, Ke-Min Jia, Cheng-Shun Xu, Xiu-Li Du, Xiao-Ling Zhang, Jia Song, Zhuo-Lin Su
Rock and Soil Mechanics
A numerical model of the liquefaction horizontal free-field shaking table test was developed based on the completed large-scale shaking table test of liquefaction horizontal free field using the OpenSees finite element platform, and the numerical model was verified. Based on this, a free-field numerical model of the overall inclined foundation was established, and the non-cyclic dynamic response of the liquefaction lateral spreading site and the mechanism of liquefaction-induced lateral spreading were discussed. The results show that the established numerical model can effectively simulate the seismic response in liquefiable sites. There was significant relative displacement at the interface between liquefiable loose …
Mechanical Response Characteristics Of Lining Structure Of Pipeline Karst Tunnels In Water-Rich Areas, Hao-Bo Fan, Ding-Kun Zhou, Yong Liu, Yu-Xiang Song, Zheng-Guo Zhu, Yong-Quan Zhu, Xin-Qiang Gao, Jia-Qi Guo
Mechanical Response Characteristics Of Lining Structure Of Pipeline Karst Tunnels In Water-Rich Areas, Hao-Bo Fan, Ding-Kun Zhou, Yong Liu, Yu-Xiang Song, Zheng-Guo Zhu, Yong-Quan Zhu, Xin-Qiang Gao, Jia-Qi Guo
Rock and Soil Mechanics
For the karst tunnel with pipeline cavities in the surrounding rock, it is very easy to accumulate high water pressure in the pipeline cavity due to the influences of heavy rainfall on the surface and groundwater, which will lead to lining cracking, water leakage, and water gushing diseases. To explore the influence of high water pressure on the lining structure, model tests of pipeline karst tunnels under high water pressure were carried out, and the internal force characteristics of tunnel lining under the influence of cavity position and water head height were studied. Based on the test findings, the numerical …
Experimental Study And Numerical Simulation On The Migration And Transformation Mechanism Of Hexavalent Chromium In Contaminated Site, Yong He, Guang Hu, Zhao Zhang, Wei Lou, Yan-Hong Zou, Xing Li, Ke-Neng Zhang
Experimental Study And Numerical Simulation On The Migration And Transformation Mechanism Of Hexavalent Chromium In Contaminated Site, Yong He, Guang Hu, Zhao Zhang, Wei Lou, Yan-Hong Zou, Xing Li, Ke-Neng Zhang
Rock and Soil Mechanics
With the rapid development of global industrialization, the pollution of hexavalent chromium (Cr(Ⅵ)) in soil and groundwater has become increasingly serious. Field investigation and laboratory tests were carried out for the soil polluted by the chromium slag of a ferroalloy plant. The adsorption, infiltration and dispersion experiments were conducted to study the adsorption characteristics and migration mechanism of Cr(Ⅵ) in silty clay. A three-dimensional kinetic mathematical model of Cr(Ⅵ) migration considering convection-dispersion-adsorption was established. The migration and distribution characteristics of Cr(Ⅵ) in groundwater with the pollution source located upstream or downstream of the contaminated site were obtained using the numerical …
Study On Rainfall Infiltration Characteristics Of Unsaturated Fractured Soil Based On Comsol Multiphysics, Xiao-Ping Hou, Heng-Hui Fan
Study On Rainfall Infiltration Characteristics Of Unsaturated Fractured Soil Based On Comsol Multiphysics, Xiao-Ping Hou, Heng-Hui Fan
Rock and Soil Mechanics
A numerical simulation study on the rainfall infiltration characteristics of unsaturated fractured soil was performed based on COMSOL Multiphysics software. By discretizing the fracture and the matrix into finite elements, a discrete fracture-porous medium model was established to fully simulate the fracture flow, matrix flow and fracture–matrix flow exchange in the soil. The upper boundary of the fractured soil was simulated by using the concept of “air element”. This method can describe not only the phenomenon of preferential infiltration for rainwater along the fractures at the beginning of rainfall, but also the phenomenon of rainwater flowing away along the surface …
Prediction Model For Compressive Strength Of Rock-Steel Fiber Reinforced Concrete Composite Layer, Meng Chen, Xiu-Wen Cui, Xin Yan, Hao Wang, Er-Lei Wang
Prediction Model For Compressive Strength Of Rock-Steel Fiber Reinforced Concrete Composite Layer, Meng Chen, Xiu-Wen Cui, Xin Yan, Hao Wang, Er-Lei Wang
Rock and Soil Mechanics
To study the uniaxial compressive strength calculation method of rock-steel fiber reinforced concrete (R-SFRC) composite layer, uniaxial compression test was carried out on rock, steel fiber reinforced concrete and R-SFRC composite layer specimens. The influence of concrete strength grades (C30, C40 and C50) and fiber contents (0, 40, 60 and 80 kg/m3) on the uniaxial compressive strength of steel fiber reinforced concrete and composite layers was analyzed. RFPA2D was utilized to simulate the damage process and stress-strain curve of the composite layer under uniaxial compression. The compressive strength prediction model of R-SFRC composite layer was established based on Mohr-Coulomb yield …
Numerical Simulation Of Open-Pit Mine Slope Based On Unmanned Aerial Vehicle Photogrammetry, Ai-Bing Jin, Shuai-Jun Chen, An-Yu Zhao, Hao Sun, Yu-Shuai Zhang
Numerical Simulation Of Open-Pit Mine Slope Based On Unmanned Aerial Vehicle Photogrammetry, Ai-Bing Jin, Shuai-Jun Chen, An-Yu Zhao, Hao Sun, Yu-Shuai Zhang
Rock and Soil Mechanics
Numerical simulation is a normal method for slope stability analysis in open-pit mines. Slope model construction is the basis of numerical simulation, and the accuracy of topographic measurement data has an important influence on the accuracy of slope stability analysis. In recent years, low-altitude and low-speed small unmanned aerial vehicles (UAVs) have been widely used in geological surveys, which provide a feasible method for rapid terrain measurement under complex conditions. Considering the situation of the rapid change of slope shape of the open-pit mine, the complex terrain, and the difficulty of manual measurement, a single-lens small unmanned aerial vehicle (UAV) …
Research On Random Propagation Method Of Hydraulic Fracture Based On Zero-Thickness Cohesive Element, Jun Li, Wen-Bao Zhai, Zhao-Wei Chen, Gong-Hui Liu, Ying-Cao Zhou
Research On Random Propagation Method Of Hydraulic Fracture Based On Zero-Thickness Cohesive Element, Jun Li, Wen-Bao Zhai, Zhao-Wei Chen, Gong-Hui Liu, Ying-Cao Zhou
Rock and Soil Mechanics
In order to effectively simulate the process of random propagation of hydraulic fractures in fractured shale reservoirs, a new method of random propagation of hydraulic fractures based on the finite element mesh embedded with zero-thickness cohesive elements is proposed. This new method is based on the topological data structure of element nodes and the splitting mode of mesh nodes. The accuracy and effectiveness of the random propagation method are verified by comparing with the analytical solution of KGD model and two kinds of laboratory experiments. Meanwhile, the influences of horizontal in-situ stress difference and reservoir heterogeneity on the process of …
Mechanism Research Of A New Constant Resistance Yielding Device For Tunnels, Chuan-Qing Zhang, Hao-An L, Xiao-Yan Liu, Hui Zhou, Yang Gao, Dong-Ming Yan
Mechanism Research Of A New Constant Resistance Yielding Device For Tunnels, Chuan-Qing Zhang, Hao-An L, Xiao-Yan Liu, Hui Zhou, Yang Gao, Dong-Ming Yan
Rock and Soil Mechanics
The constant resistance yielding support is the ideal form of support for squeezing tunnel. Current technology is difficult to satisfy the safety requirements of high bearing capacity, large deformation and load stability at the same time. In response to this problem, the constant resistance yielding device based on the principle of tension-compression conversion (CRYD-TCC) was developed inspired by the metal drawing process in combination with the working characteristics of steel arch support. In this paper, the working principle of the CRYD-TCC was discussed, and its mechanical response law and characteristics were analyzed. Through the indoor test and numerical simulation, the …
Study On Tunnel Water Inrush Mechanism And Simulation Of Seepage Failure Process, Zong-Qing Zhou, Li-Ping Li, Shao-Shuai Shi, Cong Liu, Cheng-Lu Gao, Wen-Feng Tu, Mei-Xia Wang
Study On Tunnel Water Inrush Mechanism And Simulation Of Seepage Failure Process, Zong-Qing Zhou, Li-Ping Li, Shao-Shuai Shi, Cong Liu, Cheng-Lu Gao, Wen-Feng Tu, Mei-Xia Wang
Rock and Soil Mechanics
In view of the two typical modes of water inrush disasters, progressive fracturing of rock mass and seepage failure of filling structure, the mechanism of progressive fracturing of rock mass under the combined effects of dynamic disturbance, excavation unloading and high water pressure is described. The seepage failure mechanism of the variable strength-variable permeability-variable viscosity of the filling structure under osmotic pressure is also expounded. For the variable viscosity mechanism of water inrush caused by seepage failure of filling structure, a qualitative simulation study on the effect of fluid viscosity on seepage failure mechanism is carried out using the DEM-CFD …
Single-Particle Crushing Test And Numerical Simulation Of Coarse Grained Soil Based On Size Effect, Min-Qiang Meng, Lei Wang, Xiang Jiang, Cheng-Gui Wang, Han-Long Liu, Yang Xiao
Single-Particle Crushing Test And Numerical Simulation Of Coarse Grained Soil Based On Size Effect, Min-Qiang Meng, Lei Wang, Xiang Jiang, Cheng-Gui Wang, Han-Long Liu, Yang Xiao
Rock and Soil Mechanics
The coarse-grained soil is prone to particle breakage under external loads and other factors. A series of single-particle fragmentation tests is conducted for mudstone and sandstone particles. Based on the size effect and fractal model of particle fragmentation, the relationships between the fractal dimension and single-particle crushing strength, fragmentation energy, and Weibull modulus are investigated. A single particle crushing process is analyzed using PFC3D and the modelling results are compared with that from the experimental data to verify the reliability of numerical code. The crushing strength and crushing energy of large particle size are then analyzed by numerical models. The …
Stability Analysis Of An Underground Powerhouse On The Left Bank Of The Baihetan Hydropower Station Based On Discrete Element Simulation And Microseismic Monitoring, Hao-Yu Mao, Nu-Wen Xu, Biao Li, Yi-Lin Fan, Jia-Yao Wu, Guo-Tao Meng
Stability Analysis Of An Underground Powerhouse On The Left Bank Of The Baihetan Hydropower Station Based On Discrete Element Simulation And Microseismic Monitoring, Hao-Yu Mao, Nu-Wen Xu, Biao Li, Yi-Lin Fan, Jia-Yao Wu, Guo-Tao Meng
Rock and Soil Mechanics
To investigate the stability of the surrounding rock during excavation process of the underground caverns at the Baihetan hydropower station, effects of excavation unloading on the deformation and failure of the surrounding rock using the numerical simulation software 3DEC based on DEM (discrete element method) are analyzed. The microseismic monitoring technology is introduced to monitor and analyze micro-fracture evolution inside the surrounding rock of the caverns in real time, and the numerical simulation results are compared with the microseismic monitoring data. In order to verify the accuracy of numerical simulation and microseismic monitoring results, the spatiotemporal evolution law of the …
Physical Experimental Study On Excavation Disturbance Of Tbm In Deep Composite Strata, Lin-Ken Shi, Hui Zhou, Ming Song, Jing-Jing Lu, Chuan-Qing Zhang, Xin-Jing Lu
Physical Experimental Study On Excavation Disturbance Of Tbm In Deep Composite Strata, Lin-Ken Shi, Hui Zhou, Ming Song, Jing-Jing Lu, Chuan-Qing Zhang, Xin-Jing Lu
Rock and Soil Mechanics
In view of the alternating change of soft and hard rock mass in the work face, physical model test and numerical simulation were conducted to investigate the dynamic response of tunnel surrounding rock during the process of TBM excavation in composite strata at the Lanzhou water source construction project. Similar composite rock mass materials with different strength ratios of surrounding rock were prepared by performing analogous proportion experiments. The fiber grating technology was used to capture the strain evolution law of surrounding rock in composite strata during tunnel excavation, and the macroscopic fracture morphology of the surrounding rock of the …
Development And Application Of Contact Algorithms For Rock Shear Fracture Surface, Qiu-Feng Ma, Yue-Ping Qin, Tian-Bai Zhou, Xiao-Bin Yang
Development And Application Of Contact Algorithms For Rock Shear Fracture Surface, Qiu-Feng Ma, Yue-Ping Qin, Tian-Bai Zhou, Xiao-Bin Yang
Rock and Soil Mechanics
To overcome the inefficiency of existing numerical algorithms in calculating the contact slip law of complex fracture surfaces, a new numerical calculation algorithm was proposed by adoption of the idea of boundary element method. In this algorithm, all nodes were located at the boundary of rock blocks, and the interaction force between rock blocks and the displacement of rock blocks were calculated by using the explicit differential method. The algorithm was validated by two simulation experiments, i.e. “ball sliding on paraboloid” and “dumbbell on the inclined plane”. The results show the algorithm can accurately describe the contact between objects and …
Anisotropy And Its Relation To Liquefaction Resistance Of Granular Material, Isao Ishibashi, Omer F. Capar
Anisotropy And Its Relation To Liquefaction Resistance Of Granular Material, Isao Ishibashi, Omer F. Capar
Civil & Environmental Engineering Faculty Publications
This research establishes quantitative relationships between soil's anisotropy and liquefaction resistance for granular materials. Uniform medium density (Dr = 50%) sand specimens were prepared using three different sample preparation techniques (air pluviated (AP), moist tamped (NIT), and moist vibrated (MV)) to create different initial soil fabrics. Undrained cyclic triaxial tests were then performed to determine the liquefaction resistance of each soil specimen. On the same specimens in the triaxial cell, vertical and horizontal compression wave velocities and vertical shear wave velocity (Vs) were measured using piezoelectric bender elements. Anisotropic (transversely isotropic) elastic constants of the soil specimens were …