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Full-Text Articles in Civil and Environmental Engineering

Evolution Model Of Unsaturated Shear Strength Indices Over A Wide Range Of Saturation, Yu-Xin Zhao, Xu Li, Hong-Fen Zhao, Yan Liu Dec 2023

Evolution Model Of Unsaturated Shear Strength Indices Over A Wide Range Of Saturation, Yu-Xin Zhao, Xu Li, Hong-Fen Zhao, Yan Liu

Rock and Soil Mechanics

The variation of shear strength indices of unsaturated soil with the degree of saturation Sr is complicated. In order to describe the experimental phenomena, the existing literature on the variations of cohesion, internal friction angle and dilation angle with Sr is analyzed. The results show that: (1) When Sr decreases and the pore water gradually transits from capillary water to adsorbed water, the friction angle increases. The turning point can be defined as critical degree of saturation Src. When Sr is greater than Src, the value of the friction angle is constant; when Sr is less than Src, the friction …


Classification And Damage Characteristics Of Complex Secondary Cracks In Granite Residual Soil, Cheng-Sheng Li, Bing-Xin Zhang, Zhi-Jun Liu Dec 2023

Classification And Damage Characteristics Of Complex Secondary Cracks In Granite Residual Soil, Cheng-Sheng Li, Bing-Xin Zhang, Zhi-Jun Liu

Rock and Soil Mechanics

The development of cracks is important to the damage and failure of soil. In order to study the evolution of meso-cracks in granite residual soil with complex geotechnical engineering properties, a series of reconstructed volume images was obtained by using CT to scan the process of the triaxial compression test. The crack volume overlap rate is introduced to improve the crack classification method proposed by the author, and the accuracy of judging the connectivity of the two cracks before and after deformation is improved. The results reveal that the change of crack volume overlap rate has a slight effect on …


Pull-Out Test Study On Mechanical Characteristics Of Geogrid-Aggregate Interface, Mu-Han Yan, Xian-Zhang Ling, Liang Tang, Hong Xiao, Xu-Guo Song Dec 2023

Pull-Out Test Study On Mechanical Characteristics Of Geogrid-Aggregate Interface, Mu-Han Yan, Xian-Zhang Ling, Liang Tang, Hong Xiao, Xu-Guo Song

Rock and Soil Mechanics

Geogrids are often used in the aggregate cushion of the composite foundation to limit the lateral displacement and reduce the differential deformation. It depends on the interaction between geogrids and aggregate particles. In this study, a series of large-size pull-out tests was performed on biaxial and triaxial geogrids embedded in aggregates with three particle-size gradations. The test results showed that higher normal stress, better gradation and more suitable aggregate particle sizes yielded the increase of the pull-out resistance. The classic punching-shear failure model was proven to be valid for explaining the shear effect between transverse ribs of biaxial geogrids and …


Prediction Of Consolidation Coefficient Of Soft Soil Using An Artificial Neural Network Models With Biogeography-Based Optimization, Cai-Jin Wang, Meng Wu, Yang Yang, Guo-Jun Cai, Song-Yu Liu, Huan He, Jian-Xin Chang Dec 2023

Prediction Of Consolidation Coefficient Of Soft Soil Using An Artificial Neural Network Models With Biogeography-Based Optimization, Cai-Jin Wang, Meng Wu, Yang Yang, Guo-Jun Cai, Song-Yu Liu, Huan He, Jian-Xin Chang

Rock and Soil Mechanics

The consolidation coefficient Cv of soft soil is an important parameter in geotechnical engineering. The artificial neural network (ANN) model is improved with the biogeography-based optimization algorithm (BBO). And the artificial neural network with biogeography-based optimization (ANN-BBO) model, trained and tested by using the subgrade soft soil data of the reconstruction and expansion project of Lianyungang–Huai’an expressway, has been adopted to calculate the soft soil consolidation coefficient. Using the correlation coefficient matrix and principal component analysis, eleven physical and mechanical parameters were statistically analyzed, seven of which were identified as input parameters of calculation model which was then trained and …


Effect Of Particle Swelling On Hydraulic Performance And Meso-Mechanism Of Geosynthetic Clay Liners, Juan Hou, Jin-Bang Zhang, Yin-Yu Sun, Rui Sun, Fei-Yu Liu Dec 2023

Effect Of Particle Swelling On Hydraulic Performance And Meso-Mechanism Of Geosynthetic Clay Liners, Juan Hou, Jin-Bang Zhang, Yin-Yu Sun, Rui Sun, Fei-Yu Liu

Rock and Soil Mechanics

The hydraulic performance of geosynthetic clay liners (GCL) is closely related to the swelling characteristics of the bentonite particles and the resulting porous medium. However, there currently needs to be more analysis at the mesoscopic level to understand the permeating mechanisms. A numerical model using COMSOL was developed to study the effects of particle swelling on the effective porosity, tortuosity, and hydraulic conductivity of GCL under deionized water actions. The results demonstrate that the swelling of bentonite particles is a crucial factor influencing the effective porosity, tortuosity, and hydraulic conductivity of GCL. Particle swelling significantly affects the width and number …


Study On The Environmental Durability Of Heavy Metal Contaminated Soil Remediated By Enzyme Induced Carbonate Precipitation, Han-Liang Bian, Pei-Rui Ji, Jun-Ling Wang, Xu-Gang Zhang, Xiang-Chun Xu Dec 2023

Study On The Environmental Durability Of Heavy Metal Contaminated Soil Remediated By Enzyme Induced Carbonate Precipitation, Han-Liang Bian, Pei-Rui Ji, Jun-Ling Wang, Xu-Gang Zhang, Xiang-Chun Xu

Rock and Soil Mechanics

To explore the environmental durability of heavy metal contaminated soil remediated by enzyme induced carbonate precipitation (EICP) technology, acid soaking, freeze-thaw tests, and rainfall tests were carried out on the zinc and lead contaminated soil after EICP remediation, respectively. The durability and influence of the zinc and lead contaminated soil remediated by EICP technique under different environmental conditions and the corresponding influence regularity were discussed in this paper. The results showed that under different concentrations and types of acid solutions, the leaching amount of heavy metal ions in exchangeable and carbonate bound forms in the zinc and lead contaminated soil …


Experimental Study On Rock Joint Permeability Evolution During Plugging Process By Microbially Induced Calcite Precipitation, Wei-Min Xiao, Xin Lin, Jian-Min Zhong, Shuang Li, Zhan-Yuan Zhu Dec 2023

Experimental Study On Rock Joint Permeability Evolution During Plugging Process By Microbially Induced Calcite Precipitation, Wei-Min Xiao, Xin Lin, Jian-Min Zhong, Shuang Li, Zhan-Yuan Zhu

Rock and Soil Mechanics

Microbially induced calcite precipitation (MICP) has been widely applied for soil reinforcement, but its applications in rock mass permeability reduction have been rarely reported. To explore the plugging mechanism of rock joints using MICP, artificial rock joint specimens made of transparent resin were prepared, and laboratory MICP plugging experiments under six various conditions considering MICP reaction influence factors were performed. Through the plugging experiments, evolution laws of rock joint transmissivity and hydraulic aperture, accompanied with corresponding CaCO3 distribution images, during plugging processes were obtained. The experimental results showed that the hydraulic aperture of rock joint approximately decreases linearly with grouting …


Inverse Analysis On Dynamic Shear Modulus Of Earth-Rockfill Dam Foundation Based On The Influence Of Dynamic Earth Pressure, Xiao-Shi Huang, Jun-Qing Huang, Ye-Gan Yan, Yu-Bing Wang Dec 2023

Inverse Analysis On Dynamic Shear Modulus Of Earth-Rockfill Dam Foundation Based On The Influence Of Dynamic Earth Pressure, Xiao-Shi Huang, Jun-Qing Huang, Ye-Gan Yan, Yu-Bing Wang

Rock and Soil Mechanics

The one-dimensional shear beam model method is unsuitable for determining the stress–strain relationship in the earth-rockfill dam foundation because of the constrained ground surface and the effects of the lateral normal stress. A centrifugal shaking table test was conducted on an earth-rockfill dam with overburden saturated sand foundation to analyze the soil acceleration response in the non- dam-covered area of the foundation, middle and toe of the dam under different input seismic loads. This test also obtained the variation characteristics of the horizontal dynamic earth pressure in the upper and middle layers of the dam foundation. An inverse calculation method …


Experimental Study On Shear Properties Of Fault Gouge With Different Mineral Compositions, Li-Huan Xie, He-Juan Liu, Sheng-Nan Ban, Hai-Jun Mao, De-Bin Xia, Yu-Jia Song, Rong-Chen Tong, Qi-Qi Ying Dec 2023

Experimental Study On Shear Properties Of Fault Gouge With Different Mineral Compositions, Li-Huan Xie, He-Juan Liu, Sheng-Nan Ban, Hai-Jun Mao, De-Bin Xia, Yu-Jia Song, Rong-Chen Tong, Qi-Qi Ying

Rock and Soil Mechanics

The strength parameters of fault gouge is significant for the fault sealing of underground gas storage. In this paper, direct shear tests are performed for fault gouge composed of different contents of kaolinite(K), montmorillonite(M) and quartz(Q), thus obtaining the shear strength parameters (cohesion c and internal friction angle ) of various types of fault gouge. The results reveal that: (1) the cohesion of fault gouge is positively correlated with the content of montmorillonite and negatively correlated with the content of quartz. The cohesion of fault gouge specimens with high content of montmorillonite (≥40%) is positively correlated with the content of …


Experimental Study Of Capillary Water Rising In Aeolian Sand Using A Moisture Field Testing Technique Based On Image Rgb Information, Sheng-Kui Tian, Guan-Shi Liu, Qing-Song Zhao, Guo-Fang Xu, Ming-Xuan Cai Dec 2023

Experimental Study Of Capillary Water Rising In Aeolian Sand Using A Moisture Field Testing Technique Based On Image Rgb Information, Sheng-Kui Tian, Guan-Shi Liu, Qing-Song Zhao, Guo-Fang Xu, Ming-Xuan Cai

Rock and Soil Mechanics

Capillary action has an important impact on the deformation and stability of various geotechnical engineering structures. It is challenging to accurately monitor the dynamic changes in the capillary water rising process by traditional methods. In this study, the relationship between RGB (red, green, blue) information and water content of aeolian sand images was firstly investigated. The methodology and technology for measuring water content and obtaining centimeter-level resolution moisture fields via image RGB information were developed. According to this method, the spatial-temporal variation of water content during capillary water rising in aeolian sand was further explored, and the wetting front profile …


Experimental Investigation On Quantitative Evaluation Of Rock Hardness Based On Impact Energy Dissipation Index, Rui-Lang Cao, Yu-Jie Wang, Bo Xing, Yu-Fei Zhao, Qiang Shen Dec 2023

Experimental Investigation On Quantitative Evaluation Of Rock Hardness Based On Impact Energy Dissipation Index, Rui-Lang Cao, Yu-Jie Wang, Bo Xing, Yu-Fei Zhao, Qiang Shen

Rock and Soil Mechanics

Rock hardness is an important indicator reflecting the relative hardness, drillability, and blastability of rock formation. Accurate interpretation of the response of percussion drilling tools can provide new possibilities for in-situ, rapid, and quantitative evaluation of rock hardness. High-precision digital displacement, hydraulic pressure, and rotational speed sensors were used to monitor the key transmission parts of the percussion drill, and a digital monitoring system for the drilling process was then established. Rock hardness measurement and orthogonal tests of percussion drilling were parallelly carried out, and a standard database containing response data of the drill when drilling various types of rocks …


Multi-Directional Cyclic Simple Shear Behaviour Of Loose Sand Under Complex Initial Stress States, Yao Li, Jia-Ping Li Dec 2023

Multi-Directional Cyclic Simple Shear Behaviour Of Loose Sand Under Complex Initial Stress States, Yao Li, Jia-Ping Li

Rock and Soil Mechanics

Loose sand is highly susceptible to liquefaction, and small changes in stress state can affect its liquefaction characteristics. Based on multi-directional cyclic simple shear tests, this study conducted cyclic simple shear tests on loose sand under different magnitudes and directions of static shear stress, and complex shear paths. The cyclic simple shear characteristics of loose sand under complex initial stress states are studied. The main conclusions are drawn as follows: (1) As the static shear stress ratio increases, the peak shear stress of the specimen increases, the increment of pore water pressure in the first cycle increases, and the specimen …


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 Dec 2023

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, …


Numerical Simulation Of Three-Dimensional Rock Fragmentation By Disc Cutters Of Tunnel Boring Machine Using Peridynamics, Jian Zhou, Xiao-Nan Shang, Fu-Shen Liu, Jun-Yi Shen, Xing-Chuan Liao Dec 2023

Numerical Simulation Of Three-Dimensional Rock Fragmentation By Disc Cutters Of Tunnel Boring Machine Using Peridynamics, Jian Zhou, Xiao-Nan Shang, Fu-Shen Liu, Jun-Yi Shen, Xing-Chuan Liao

Rock and Soil Mechanics

Peridynamics is a non-local mesh-free numerical method which has great advantages in simulating dynamic damage and fracture. This work proposes to use the peridynamics to simulate rock fragmentation by TBM disc cutters and seven tests are simulated to verify this idea. The feasibility of peridynamics in simulating rock fragmentation by TBM disc cutters is demonstrated by comparisons with the punch indentation tests. A nonlinear short-range force contact model is proposed to better reflect the variation of the disc cutter normal force with respect to indentation depth, and can also calculate the changing contact area between the disc cutter and the …


Shaking Table Test Study On The Influence Of Seismic History On Liquefaction Resistance Of Soils At Different Depths, Xiao-Lei Wang, Li-Teng Liu, Run Liu, Li-Bo Liu, Lin Dong, Hai Ren Dec 2023

Shaking Table Test Study On The Influence Of Seismic History On Liquefaction Resistance Of Soils At Different Depths, Xiao-Lei Wang, Li-Teng Liu, Run Liu, Li-Bo Liu, Lin Dong, Hai Ren

Rock and Soil Mechanics

Earthquake-induced liquefaction can cause significant damage to geotechnical structures, and the aftershocks accompanying the earthquakes may cause the sandy soils to liquefy again. To investigate the effect of free-field subsurface seismic history on the liquefaction resistance of saturated sandy soils at various depths, a series of shaking table tests was designed and conducted. Four shaking events with different accelerations, subdivided into seven smaller events, were input to the sandy soil in the tests. The excess pore pressure ratio, acceleration response, and soil settlement were calculated and compared for each vibration event to investigate the variation laws of soil liquefaction resistance …


Dynamic Response And Effect Of Loading Rate Of Soil Under Impact Loading, Yong-Jian Liu, Yang-Pan Fu, Ming-Yang Lai, Zhang-Ming Li, Hao-Yuan Fang, Zhi-Kun Xie Dec 2023

Dynamic Response And Effect Of Loading Rate Of Soil Under Impact Loading, Yong-Jian Liu, Yang-Pan Fu, Ming-Yang Lai, Zhang-Ming Li, Hao-Yuan Fang, Zhi-Kun Xie

Rock and Soil Mechanics

To study the dynamic response characteristics of soil under impact load, plate dynamic load tests (PDLT) with different load levels and loading rates were carried out on two typical soils (sand and clay) in Guangzhou University Town by using the self-developed additional excitation force-type PDLT system, obtaining three characteristic curves of load-time curve, displacement-time curve, and load-displacement curve, establishing the empirical formula of dynamic deformation modulus and loading rate, and comparing the effects of loading rate of the two soils under impact load. It shows that: (1) There is a threshold of charging voltage in the PDLT test of sand. …


Lining–Stratum Interaction Mechanism Of Mountain Tunnel Based On Static Pushover Model Test, Qin-Wu Lu, Zhen-Chang Guan, Lin Lin, Shu-Jing Wu, De-Jie Song Dec 2023

Lining–Stratum Interaction Mechanism Of Mountain Tunnel Based On Static Pushover Model Test, Qin-Wu Lu, Zhen-Chang Guan, Lin Lin, Shu-Jing Wu, De-Jie Song

Rock and Soil Mechanics

With the rapid development of traffic infrastructure construction in western mountain area, the lining-stratum interaction mechanism of mountain tunnel under seismic effects has attracted increasing attentions. Based on the prototype of a regular two-lane highway tunnel section with V-grade surrounding rock, a static pushover model test for mountain tunnel was conducted. The variations of stratum displacement, stratum strain and ground pressure with pushover distance were carefully studied, and the lining-stratum interaction mechanism was thoroughly discussed. The test results show that: the lining-stratum interaction can be generally divided into compacting stage, overturning stage, and dragging stage. The stratum tends to circumferentially …


Temperature Effect On Water Retention Capacity Of Nanning Expansive Soil And Its Microscopic Mechanism, Zhao-Tian Zeng, Zhe-Qi Cui, De-An Sun, Zhi Yao, Bin Pan Dec 2023

Temperature Effect On Water Retention Capacity Of Nanning Expansive Soil And Its Microscopic Mechanism, Zhao-Tian Zeng, Zhe-Qi Cui, De-An Sun, Zhi Yao, Bin Pan

Rock and Soil Mechanics

To explore the variation of water retention capacity of expansive soil at different temperatures, the calibration curves of Whatman No.42 filter paper were measured by vapor equilibrium method at 5, 25, 40 ℃ and 60 ℃, and the bilinear calibration equation considering temperature effect was established. The results show that the water retention capacity of the filter paper decreases with the increase of temperature, and the effect on the high suction section of calibration curve is weaker than the low suction section. On this basis, Nanning expansive soil is taken as the research object, and the soil-water characteristic curves of …


Effects Of Skeleton Void Ratio On The Strength And Deformation Characteristics Of Coarse-Grained Soil, Jia-Jun Pan, Xiang-Jun Sun, Yong-Zhen Zuo, Jun-Peng Wang, Yi-Wei Lu, Bing Han Dec 2023

Effects Of Skeleton Void Ratio On The Strength And Deformation Characteristics Of Coarse-Grained Soil, Jia-Jun Pan, Xiang-Jun Sun, Yong-Zhen Zuo, Jun-Peng Wang, Yi-Wei Lu, Bing Han

Rock and Soil Mechanics

The strength and deformation characteristics of coarse-grained soil are closely related to the initial gradation and dry density during specimen preparation. To study the strength and deformation characteristics of coarse-grain materials with different gradations and densities, a simple and generalized method for calculating the skeleton void ratio of coarse-grained soil is proposed. The results of laboratory tests show that there is an obvious monotonic variation between the skeleton void ratio obtained by this calculation method and the mechanical properties of coarse-grained soil. When the specimen size is consistent, with the decrease of the skeleton void ratio, the failure shear stress …


A Study About The Influence Of Joint Roughness On The Volume Of Rock Blocks, Tie-Xin Liu, Jia-Qi Li, Jian-Hui Deng, Zheng-Hu Zhang, Jun Zheng Dec 2023

A Study About The Influence Of Joint Roughness On The Volume Of Rock Blocks, Tie-Xin Liu, Jia-Qi Li, Jian-Hui Deng, Zheng-Hu Zhang, Jun Zheng

Rock and Soil Mechanics

The structure of a rock mass directly controls its mechanical and hydraulic properties, and the distribution of rock block volumes can directly reflect the structural characteristics of the rock mass. Currently, many studies simplify the joint surfaces as planes and ignore the influence of roughness on the volume of rock blocks. In this study, the Hurst exponent (H) and root-mean-square height (Rq) were used to characterize joint roughness, and the influence of joint roughness on the quantity and volume distribution of rock blocks was investigated. The results show that: (1) H and Rq control the roughness of the joint, and …


A Calculation Method For Deformation Of Diaphragm Wall Of Narrow Deep Foundation Pit In Soft Soil Considering Spatio-Temporal Effect, Kun-Yong Zhang, Meng Zhang, Bin Sun, Fu-Dong Li, Yong-Zhou Jian Dec 2023

A Calculation Method For Deformation Of Diaphragm Wall Of Narrow Deep Foundation Pit In Soft Soil Considering Spatio-Temporal Effect, Kun-Yong Zhang, Meng Zhang, Bin Sun, Fu-Dong Li, Yong-Zhou Jian

Rock and Soil Mechanics

To accurately evaluate the safety of foundation pit construction in soft soil area and its impact on the surroundings, the time and space influencing factors during excavation cannot be ignored. In this paper, based on the excavation of a deep foundation pit in the soft soil area of the Yangtze River floodplain, a 3D finite element model was established considering the combination of bottom-up and top-down constructions, and the calculated values of horizontal displacement of the diaphragm wall were compared with the measured values to verify the reliability of the finite element calculation. Based on theoretical analysis, numerical calculation and …


Reliability Analysis Of Rock Tunnel Stability Based On Interval Non-Probability Under Multiple Failure Modes, Xiang Li, Jing-Tong Wang, Heng Wei Dec 2023

Reliability Analysis Of Rock Tunnel Stability Based On Interval Non-Probability Under Multiple Failure Modes, Xiang Li, Jing-Tong Wang, Heng Wei

Rock and Soil Mechanics

For the reliability analysis of rock tunnel stability, considering the difficulty in obtaining the statistical data on rock mass parameters, there is the potential inadequacy when using the probabilistic reliability method; on the other hand, the rock tunnel stability is intimately pertinent to a variety of failure modes, meaning it is necessary to consider the issue on structural system reliability. First, based on the interval theory, the uncertainty parameters were represented by adopting the interval variables. Subsequently, aiming at the coexistence of multiple failure modes in rock tunnel engineering, the concept of structural system reliability was introduced, and then a …


Experimental Study On Sand Anti-Seepage By Microorganism–Bentonite Combined Mineralization, Yu Zhang, Xiang He Dec 2023

Experimental Study On Sand Anti-Seepage By Microorganism–Bentonite Combined Mineralization, Yu Zhang, Xiang He

Rock and Soil Mechanics

The seepage of sandy foundation would lead to the collapse of foundation and the destruction of engineering structure. A series of large-scale sand column seepage model experiments was carried out by using microorganism–bentonite combined mineralization method. The in-depth discussion was conducted for the effects of sand particle size, slurry liquid-to-solid ratio and treatment cycles on the permeability, internal erosion characteristic and bentonite and calcium carbonate precipitate distribution of sand. Moreover, the stability of sealing and the microstructure were thoroughly investigated, and the treatment effect of microorganism–bentonite combined mineralization method was evaluated. It was found that this method could improve the …


Optimal Strut Position Of Deep Foundation Pit With Convex Corner Under Surcharge Of Adjacent Building, Bao-Guo Chen, Zeng-Pan Jia Dec 2023

Optimal Strut Position Of Deep Foundation Pit With Convex Corner Under Surcharge Of Adjacent Building, Bao-Guo Chen, Zeng-Pan Jia

Rock and Soil Mechanics

Since the mechanical behavior of the convex corner is complex due to surcharge near the excavation, it is of great importance to evaluate the influence of changes in strut position on the convex corner. Field monitoring and numerical simulations were used to analyze the influence law of the changes of strut position on the deformation and stress characteristics of the convex corner area. The axial force of inner strut, the lateral earth pressure on the pile, the horizontal displacement of the pile, the settlement of adjacent building and the bending moment of the pile were obtained. The research results show …


Investigation Of The Fracture Process Zone And Behavior Of The Macro-Scale Fatigue Cracks In Brittle Rock Specimens, Nazife Erarslan Nov 2023

Investigation Of The Fracture Process Zone And Behavior Of The Macro-Scale Fatigue Cracks In Brittle Rock Specimens, Nazife Erarslan

Rock and Soil Mechanics

The importance of this study is to explain the fatigue damage mechanism while addressing the effect of fatigue on the fracture toughness (KIC) using the brittle Brazilian specimens and to show for the first time in the literature the behavior of macroscale cracks that open and close in brittle rock without leading to eventual failure. The KIC was reduced by 35% due to the cyclic loading, and the reduction of the indirect Brazilian strength was found to be reduced by 30%. The fatigue cracks were observed to open and close elastically without failure and have been recorded by a camera …


Mode I Crack Morphology And Fracture Surface Roughness Of Granite Under Impact, Xue-Song Wang, Lian-Jun Guo, Xin Liu, Ding Deng, Jiu-Yang Zhang, Zhen-Yang Xu Nov 2023

Mode I Crack Morphology And Fracture Surface Roughness Of Granite Under Impact, Xue-Song Wang, Lian-Jun Guo, Xin Liu, Ding Deng, Jiu-Yang Zhang, Zhen-Yang Xu

Rock and Soil Mechanics

To study the response of mode I cracks under impact loading, the dynamic fracture test on the single cleavage triangle (SCT) granite specimens with the lateral opening was carried out using a split Hopkinson pressure bar test system. The Hough transform method was used to quantitatively describe the distributions of the surface crack lengths and angles, and the relationship between them and the absorbed energy of the specimen was analyzed. The three-dimensional (3D) point cloud data of the fracture surface was obtained by using a 3D surface topography detection device, and a fracture surface reconstruction method based on the threshold …


Upper Bound Analysis Of Uplift Piles In Saturated Clay And Soil Plug Effect, Ke-Wen Zhu, Jian Yu, Mao-Song Huang Nov 2023

Upper Bound Analysis Of Uplift Piles In Saturated Clay And Soil Plug Effect, Ke-Wen Zhu, Jian Yu, Mao-Song Huang

Rock and Soil Mechanics

A new mechanism is established and applied to the upper bound analysis of uplift piles in saturated clay. Upper bound solutions of uplift capacities of closed and open-ended piles are analyzed. The new mechanism is verified by comparing with elastoplastic finiteelement, existing lower bound and API solutions. Its reliability is assessed through case studies including one centrifuge test and two field tests. The effects of the pile length-diameter ratio, pile surface roughness, non uniformity of undrained soil strength and length of soil plug on the uplift bearing capacity are considered. A formulation predicting the net bearing capacity of closed-ended uplift …


Shear Strength Characteristics Of Unsaturated Rubber Silt Mixtures, En-Quan Zhou, Yuan Yao, Lei Cui, Long Wang Nov 2023

Shear Strength Characteristics Of Unsaturated Rubber Silt Mixtures, En-Quan Zhou, Yuan Yao, Lei Cui, Long Wang

Rock and Soil Mechanics

To study the shear strength characteristics of unsaturated rubber silt mixtures, a series of direct shear tests was conducted on the rubber silt mixtures with different rubber particle contents and water contents. Based on the particle contact state theory, the meso contact mode of rubber silt mixtures was constructed, and the calculation method of rubber silt mixtures skeleton void ratio based on different rubber content was obtained. The test results show that the shear strength of rubber silt mixtures decreases with the increase of skeleton void ratio at a low water content, while the strength of rubber silt mixtures increases …


A Simplified Algorithm For Predicting Creep Settlement Of High Fill Based On Modified Power Law Model, Jian Huang, Pu-Rong De, Yang-Ping Yao, Ren Peng, Ji-Lin Qi Nov 2023

A Simplified Algorithm For Predicting Creep Settlement Of High Fill Based On Modified Power Law Model, Jian Huang, Pu-Rong De, Yang-Ping Yao, Ren Peng, Ji-Lin Qi

Rock and Soil Mechanics

The creep settlement dominates the long-term deformation of high fill foundation after construction and cannot be ignored. The reliable prediction of creep settlement provides an important guideline for judging whether settlement is stable and arranging subsequent construction. The modification of the traditional power law model for predicting the one-dimensional creep deformation of soil is proposed, which can describe the one dimensional creep deformation of clay, sand and soil-rock mixture. The modified model satisfies the requirement that the growth of the creep deformation has an asymptote with respect to time; that is to say, the creep deformation grows continually and approaches …


Probabilistic Evaluation Of Excavation Unloading Response Of Rock Slope Considering The Uncertainty Of Mechanical Parameters, Guo-Feng Liu, Kun Feng, Chang-Gen Yan, Guang-Liang Feng, Ding-Ping Xu, Chi Zhou Nov 2023

Probabilistic Evaluation Of Excavation Unloading Response Of Rock Slope Considering The Uncertainty Of Mechanical Parameters, Guo-Feng Liu, Kun Feng, Chang-Gen Yan, Guang-Liang Feng, Ding-Ping Xu, Chi Zhou

Rock and Soil Mechanics

There are many studies on the spatial variability of mechanical parameters of jointed rock masses and the reliability of slopes with potential slip surface, but the research on the spatial variability of mechanical parameters of rock slopes and the uncertainty analysis of excavation unloading response (deformation and plastic zone) is limited. A probabilistic evaluation method for excavation unloading response of rock slopes considering the uncertainty of mechanical parameters is proposed. Based on laboratory rock mechanical tests and geological survey mapping data, the probabilistic statistical models of rock mass mechanical parameters of slopes are constructed by using Hoek-Brown empirical criterion and …