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30 December 2020, Volume 34 Issue 6 Previous Issue    Next Issue

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Application of Double Row Piles with Rakersas the Deep Excavation Support Structure in Guizhou Red Clay DENG Yu, MENG Baohua, GUAN Qianyuan, ZENG Zhipeng 2020, 34 (6):  639-643.  Abstract ( 325 )   Save A deep excavation site in Guizhou was in the read clay soils. After completion of the drilling of the planned double row supporting piles, the design excavation depth increased by three meters. After further evaluation, it was decided to maintain the original double row pile supporting structure with additional internal support with rakers. Other measures, improved walers, increasing the reinforcement in the cast-in-place concrete piles, preserving the rock layer in front of the soldier pile were also utilized. Furthermore, the construction monitoring results indicated that the strength of red clay is higher than the code suggested reduction values. The paper also recommends that geotechnical investigation during construction should be performed so that the site conditions could be better understood. The recommended horizonal displacement value at the bottom of the excavation should be 5 mm. Related Articles | Metrics

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Pile Design forA High Tower Foundation in Liquefiable Sites GU Cuilian 2020, 34 (6):  644-647.  Abstract ( 345 )   Save The high absorption tower is constructed in 8 degree high intensity seismic zone and liquefaction site in Inner Mongolia.Designing the pile foundation correctly is the main factor of the engineering success. The wind and seismic load effect which is needed in tower foundation design and the characteristic value of bearing capacity of single pile during normal and seismic liquefaction is analysed, and The load combination of normal operation, waterfilled pressure test, shutdown maintenance and earthquake action is calculated based on Design Code and PKPM Software. It is concluded that seismic action is the control condition of pile foundation design in high intensity area of liquefaction site. As well as the influence of pile foundation thick cap effect on engineering. The results can be reference for the similar projects.     Related Articles | Metrics

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Deep Excavation in Soft Soils Adjacent to Historical Buildings ZHU Changsheng 2020, 34 (6):  648-651.  Abstract ( 267 )   Save With the popularization of urban rail transit, more and more deep excavation projects are carried out in urban areas. In the more developed cities, most of the strata are formed by alluvium near rivers. Under such geological conditions, the proposed construction is increasingly faced with the issues associated with historical building protection. By the scientific and comprehensive use of technical measures such as waler wall reinforcement, new composite bentonite and axial force controlled system, the deformation control of foundation excavation can be significantly improved and the impact of the construction on the environment can be reduced. This paper presents a metro station excavation in Nanjing area as an example. The paper adopts these technical measures as waler wall reinforcement, new compound bentonite, axial force controlled system, and scientific decompression and recharge as needed. All these parameters of the foundation excavation support construction were within the controllable range, and the comprehensive application of the above measures could better solve the concerns of the historical building preservations. Related Articles | Metrics

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Analysis of Landslide Induced Geological Hazards and Recommendations for the Early Warning System and Landslide Mitigation Measures ZHAO Yejiang 2020, 34 (6):  652-655.  Abstract ( 339 )   Save A large landslide occurred in the township of Wuyang, Zhenyuan County, Guizhou Province. This paper presents the regional geological environment conditions, topography, tectonic geology, hydrogeology, engineering influence and other factors that might induce the geological hazards such as landslides. Further, the triggering factors of the landslide are summarized. A simplified geological hazard early warning and forecast system was established in the field. Based on the site investigation results, supporting measures that are safe, reliable, cost effective, environmentally friendly and vegetation measures are recommended. Related Articles | Metrics

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Installation of Closely Spaced Bride Supporting Piles on Existing Metro Tunnels SHU Chang, LIU He 2020, 34 (6):  656-659.  Abstract ( 251 )   Save Based on the Middle Bridge Project of Chaoyang Dagou that overcrossing the existing metro tunnel in Changzhou City, this paper presents the influence of installations of closely spaced bridge supporting piles on the existing metro tunnels by the field construction monitoring and three-dimensional finite element simulation results. The results show that the closely spaced pilesinstalled by the low disturbance grouting reinforcement around piles and advance support of the steel casing has no significant impact on the metro tunnel structures. During the entirepile construction process, the deformations of the metro tunnel were within the acceptable controlling range, and the tunnel structure was determined to be safe. The metro tunnel structure is sensitive to the external vibro-impact loadings. When the pile installation method was changed to impact drill bits in adverse geological conditions, the influence of vibration on the deformation of track segments inside the tunnel should be carefully considered. The entire process of the pile foundation construction and post-construction service loadingare simulated by the finite element software, and the deformations from the analytical results and field monitoring data are compared. After the external bridge structure loadsare applied, the tunnel mightresult in deformations, therefore, it is necessary to emphasis the post-pile installation monitoring to ensure the safety of the metro tunnel structure. Related Articles | Metrics

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Application of Heavy Dynamic Cone Penetration in the Characterization of Jiajiang Cobble Soils XU Kaidi, JIANG Wei, NIE Liqi, LI Yu 2020, 34 (6):  660-662.  Abstract ( 386 )   Save The dynamic cone penetration test (DCPT) is one of the conventional insitu test methods in the geotechnical engineering investigations. It is widely used both domestic and abroad. It uses a weight falling from a certain height to penetrate the standard sized cone tip into soils with a predefined depth. The blow counts that are required to reach the cone penetration depth are then recorded and used to characterize the engineering properties of subsurface soils. This paper summarizes the application of a heavy dynamic cone penetration in the investigation of cobble soils for the Jiajiang Airport project. The cobble soil stratigraphy and bearing resistance parameters were obtained from the DCPT. The results indicate that the DCPT method could be used in the exploration of cobble soils. Related Articles | Metrics

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Stability Evaluation and Engineering Mitigation Recommendations of Waste Soil Storage Yard for an ExpresswayProject in Mountain Area LI Chun, LIANG Dongcai, YANG Xiaoquan 2020, 34 (6):  663-666.  Abstract ( 291 )   Save Waste soil storage yards are frequently encountered in the expressway construction in mountainous areas. The stability of these storage yards directly affects the construction of the adjacent highway subgrade and other structures. This paper presents the stability investigations of waste soil storage yard for a highway widening project in Yunnan Province. Throughout the field investigation, laboratory tests, numerical simulation on the storage yard, actual design details and constructability, the waste soil storage slope were rearranged. The recommended waste soil slope was analyzed under various conditions, such as, normal working, saturated, weak waste soil lenses and different levels of perched water. It is also recommended that the drainage measures to be installed at the surface of the proposed waste soil slope to minimize the stability risks induced by the erosion and the accumulation of the perched water. Related Articles | Metrics

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Design and Remediation Measures of Taiping Tunnel Through Large Karstic Rock Cavern SONG Zidong 2020, 34 (6):  667-670.  Abstract ( 401 )   Save During the construction of Taiping tunnel of Xuanhe Expressway in Hubei Province, a large karstic cavern was encountered. The rock cavern had the characteristics of large size, a large number of broken rocks accumulated at the bottom and the high probability of falling rock hazards from top of rock cavern, which brought great difficulties to the tunnel excavation. Through the geological survey of karst rock cavern, this paper presents a design approach that spanning over the rock cavity to ensure the safety of workers during the construction and to reduce the operation cost in the service. Related Articles | Metrics

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Single Pile Axial Resistance Estimation of Piles Socketed in Soft Rock Formations XIE Yifan, ZHU Shouzeng, XIE Baocheng 2020, 34 (6):  671-674.  Abstract ( 327 )   Save The weak-and hard alternating rock layers are frequently encountered in the sedimentary rock formations. However, these rock strata, especially, weak rock layers, are the unfavorable geological conditions for the rock socketed piles. In order to accurately determine the axial bearing resistance and the rock socketed depth, the performance of the weak-and-hard alternating rock layers should be thoroughly investigated. If the compressive strength of rock loading bearing layer are low or the assumed design values are low, the total bearing resistance of the rock socketed pile could be achieved by using a larger diameter pile or a deep rock socketed length. When pile tip is at the slightly weathered rock layer and the shaft is penetrating one or more weak zones, the side frictions in the weak rock layer should be reduced. Related Articles | Metrics

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Influence of Deep Excavation on Stability of Utility Pipes Penetrating the Supporting Walls YANG Qingguang, LIU Xiong, DENG Fanggen 2020, 34 (6):  675-680.  Abstract ( 284 )   Save In order to study the influence of deep excavation on the stability of underground utility pipelines that penetrating the supporting wall with different intersection angles, a three-dimensional numerical model of the structure-soil-underground pipeline interaction was established by using FLAC3D commercial software that considering different intersection angles and various excavation depths. The vertical displacement, vertical stress, and axial force in pipelines, which have an important impact on the pipeline stability, are investigated. The results show that when the excavation is in stages 13, the vertical displacement curves of the pipelines at different intersection angles are symmetrically distributed, while in the stages 4-6, the vertical displacement of the pipelines is asymmetric, and the smaller the intersection angle is, the more obvious the non-uniformity of the vertical displacement curve. With increase of the excavation depth, an apparent dipping of the pipeline inside the excavated area was observed. When the included angle is 90°, the vertical stress curve of the pipeline within the range of the excavated area is close to horizontal, and the axial force distribution of the pipeline is “mountain peak”. Whether the axial force curve obtained by considering the orthogonality between the pipeline and the excavated area has a large value of difference. When the included angle is 60°, 74.74° and 80°, a large stress concentration occurs near the supported wall, and a stress concentration also occurs in the middle of the pipeline inside the excavated area. The axial force distribution of the entire pipeline is a sharp “valley” shape. The largest positive axial force appeared near the pit wall, and the largest negative axial force appeared near the middle of the excavated area. Related Articles | Metrics

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Development of Three-Dimensional GIS in Geological Modeling PAN Yajing 2020, 34 (6):  681-684.  Abstract ( 357 )   Save The traditional two-dimensional GIS in the geological modelling only uses the elevation as the attribute of geographic elements and has no elevation coordinates associated. Therefore, with the advancement of social science and technology, this modelling method has encountered bottlenecks in many applications.Due to its powerful geospatial object modeling and spatial analysis capabilities, the current three-dimensional GIS modelling has a good application in geological aspects, mining, environment, measurement, and biology. This paper introduces the current technology and applications of GIS based on drilling data in the geological space and visualization in recent years. It is also reviewed the development history of the GIS with a focus on the technical problems and development trends of the 3D GIS research and exploration. Related Articles | Metrics

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Numerical Simulation of a Cut and Cover Tunnel LIU Feng, DONG Xiaowei 2020, 34 (6):  685-688.  Abstract ( 369 )   Save The performance of the supporting structure and the excavation process of a cut and cover tunnel were numerically simulated by using ANSYS software. The deep soil deformation and the ground subsidence adjacent to the deep excavation areas are presented. The results indicate that performance excavation and the support structure are the problem of interactions among the supporting structure, soil inside the excavated area and soil behind the supporting structures. The supporting structure selections have a significant influence on the adjacent environments, soil behind the structure and the soil inside the excavated area. Related Articles | Metrics

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Finite Element Analysis of Shallow Buried Tunnel Segment Structure Tests BAO Zechen 2020, 34 (6):  689-694.  Abstract ( 350 )   Save This paper presents the technical aspects and the advantages of a tunnel excavation method, Ground Pass Shield Tunneling (GPST). The analytical methods of stress in the segment tunnel structure is also introduced in the paper. The 16 points concentrated loading method used in the laboratory model test of the internally loaded segment structure under the GPST conditions with very shallow cover soil depth or negative cover depth are also compared with the numerical analysis by using the equivalent bending moment principle. The results indicate that the bending moment and deformation information obtained from both methods are close but there are large differences in the axial and shear loads. However, the key factors for the potential cracks in the tunnel structure under the shallow cover and negative cover depth are excessive bending moment and deformation, which could be satisfactorily obtained throughout the 16 points loading method. Related Articles | Metrics

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Improvement of Peck Formula in Multiline Overlapped Shield Tunnel Construction in Shanghai ZHANG Bin 2020, 34 (6):  695-698.  Abstract ( 430 )   Save The Peck Formula is often used to predict the surface settlement dur to the tunnel excavation. The influence of various factors that might cause the surface settlement during the tunnel excavation and these factors might lead to a large settlement prediction error. In this paper, based on the construction monitoring data during the overlapping construction of the four lines of tunnels between Xujiahui Station and Shanghai Gymnasium Station of Shanghai Metro Line No.11, the width correction coefficient of the settlement trough and the maximum settlement correction coefficient of the surface are introduced, and the Peck Formula was improved and corrected to meet the requirements of the construction conditions. The monitored data indicated that, when the maximum settlement correction coefficient of the surface was between 0.2 and 1.2 and the correction coefficient of slot width is between 0.4 and 1.6, a good settlement prediction curve can be obtained. Related Articles | Metrics

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Groundwater LevelforUplift Control in the Geotechnical Investigation of Buildings in Rolling Hill Area TANG Daqian , GE Yanming 2020, 34 (6):  699-701.  Abstract ( 571 )   Save The groundwater level for uplift control directly affects the construction cost and the structure safety.This paper starts from the definition of the groundwater level for uplift control in the design code. Then, the paper presents a case history of determination of groundwater level for the uplift control in accordance with groundwater seepage relations. When a large area of high fills on the site, the effect of raising the groundwater level should be considered int eh design. Different groundwater level for the uplift control during construction and the service. Related Articles | Metrics

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Study on Engineering Geological Zoningand Bearing Capacity of Shallow Silt Soil in east of Henan Region WANG Wentao 2020, 34 (6):  702-705.  Abstract ( 399 )   Save This paper summarizes the geotechnical exploration results in urban Shangqiu area over the years. Combined with regional geological conditions and topographical information, the widely covered silty soil in shallow depth was analyzed from its deposition mechanism, distribution and engineering properties. Three zones were classified based on the topographical characteristics. The laboratory test results of physical indices and mechanically properties of silty soil samples from each zone were statistically evaluated and compared with the in-situ plate load tests and other insitu test results. The bearing capacity properties of the shallow buried silty soils were established.  Related Articles | Metrics

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Relationship between Rock CoreDiscingand Geostressin Jinping Underground Laboratory ZHOU Jifang 2020, 34 (6):  706-710.  Abstract ( 514 )   Save Rock core-discing is a special mechanical behavior of the rockmass under high in-situ stress conditions. Based on the precious field data of deep rock core-discing, figuring out the characteristics, laws of core-discing and the relationship with stress is of great significance to promote the understanding and theoretical development of deep rock mechanics phenomena. Based on the rock core cake formation data from some boreholes in the Jinping Underground Laboratory,which is the deepest in the world, this paper conducts a statistical analysis of the rock corediscing phenomenon, and examines the occurrence conditions of the rock core-discing, the statistical characteristics of the core disk thickness, and the evolution pattern of the rock core-discing with the drilling depth. The results of this investigation show that the rock core-discing phenomenon is likely to occur in the intact rock masses in the higher stress area; the amount of rock core disk generally decreases with the increase of the borehole diameter, and the thickness of the core disk increases as the diameter of the core increases, the ratio of the thickness of the rock disk to the diameter in different diameter boreholes is distributed between 0.2 and 0.25; the thickness of the cake disk and the maximum principal stress satisfy a negative exponential function relationship. Related Articles | Metrics

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Experimental Study of the Permeability Characteristics of EHP FENG Ying, XIAO Yan, JI Feng, SONG Miaomiao, WENG Jiaxing 2020, 34 (6):  711-714.  Abstract ( 391 )   Save The Environmental Homogeneous Cementsoil Mixed Pile (EHP) is a new type of cementsoil mixing pile developed from the conventional installation of soilcement mixed pile. The soilcement samples were prepared in field and laboratory, respectively. A series of permeability tests and Scanning Electronic Microscope (SEM) tests were conducted on the mixtures to investigate the effects of reinforced depth, cement content and curing environment on the permeability of EHP. The results indicate that hydraulic conductivity of EHP keeps almost unchanged with increase in the depth. The increase in the cement content and sample curing time induce a reduction in the permeability of cement soil although the overall decrease is small. For samples cured under the standard conditions, the values of permeability are usually larger that than cured in the field. But the difference in the permeability of samples cured under different environment, would decrease with the increase in the cement content. Related Articles | Metrics

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Physical and Mechanical Properties of Topsoil in an Offshore Wind Farm in Guangdong XU Hong, XU Xiaozhen, HUANG Wei, GAO Yuan, MA Zhe, WANG Yin 2020, 34 (6):  715-720.  Abstract ( 434 )   Save Based on the key technology research of the application of the cylindrical foundation in offshore wind power engineering projects and the requirements of the foundation design, this paper analyzes the cylindrical samples collected from more than 20 meters deep and shallow water area of an offshore wind turbine project site in Guangdong Province, explores the basic physical and mechanical properties of the seabed surface soil in this area, and obtains the parameters and indexes of the seabed surface soil in this area. The results show that the surface soil is classified as clay or silty clay, and the physical and mechanical properties of the surface soil vary in different stations and depths, which is significantly different from the sediment properties in other offshore areas; the natural water content and AtterbergLimits are low, the void ratio is small, and the water retention capacity of the surface soil in this area is poor; the particle gradation curve of surface soil is continuous and the gradation difference in the surface soil is not significant. The direct shear strength of the soil samples at different stations is different, but there is regularity and unity along the depth. The full flow penetration Tbar test suitable for low strength soil is used to measure the strength of undisturbed and remolded soil samples. The undrained shear strength of soil increases with the increase of depth, and the sensitivity is basically in the middle sensitivity range. Through a series of analysis and research, the physical and mechanical properties of the surface soil on the seabed of the site are obtained, which not only provides the key geological survey and design data for design and construction projects in the area, but also provides an important reference for the future study of the mechanical properties of the sediment in the offshore soils. Related Articles | Metrics

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Field Load Test on Axial Capacity of a New Composite Pile LI Xingbing, LI Hui, JI Feng, QIANG Chengcang, QIU Chengchun 2020, 34 (6):  721-724.  Abstract ( 309 )   Save The Environmental Homogeneous Plastic (EHP)pile is a new cement-soil mixing pile type with the controlled physical and mechanical properties. The pile is installed by injecting the environmentally friendly homogeneous plastic materials into the borehole. The new material for the pile has the advantages over the soil-cement mixed columns that usually have the issues of non-uniform, discontinued column shafts and low shaft strength. The field static plate loading tests were performed on composite soil and piles mixed with three different cement contents: 8%, 10% and 13% and the test results were compared with the conventional composite ground formed by the conventional soilcement mixing columns.The results show that neither the single pile nor the composite foundation is loaded to failure, and the load settlement curveshave gradual deformation pattern.The cumulative settlement under the maximum load decreases with the increase of the cement content as a power function. At the same cement content, the deformation resistance of the EHP pile and composite foundation is better than that of the conventional soilcement mixing columns, and the cement ratio can be reduced when the improvement effect is evident. The axial bearing capacity of EHP single piles and the composite foundations can meet the design requirements as well as cost effective for the project. Related Articles | Metrics

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Experimental Studies of Reinforced Fibers in All Recycled Material Mixtures ZHANG Wei, CHEN Jianchun 2020, 34 (6):  725-727.  Abstract ( 251 )   Save The test results show that the mechanical properties of the recycled material mixtures can be improved by blending fibers. The monofilament polypropylene fiber was used in this experimental study. It was concluded that the optimal fiber content was 0.08% ~ 0.12% by the weight of the recycled mixtures. With the increase of curing age, both the compressive strength and tensile strength of the fiber mixed recycled material samples are improved. The strength in the later stage is significantly higher than that of the samples without adding fibers. From the characteristics of the stressstrain curve, the strength increase is mainly occurred the elastoplastic deformation stage. The results show that the compressive strength of the mixture is about 25% higher than that of the mixture without fibers, and the failure characteristics of the mixture basically conform to the Mohr Coulomb relationship. When the fiber content is within a reasonable range, the shear failure surface increases with the increase of fiber content. Related Articles | Metrics

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Influence of Soil Resistivity Affected by Freezing CHEN Lihao, LI Ying 2020, 34 (6):  728-731.  Abstract ( 340 )   Save The frequent freeze-thaw cycleshave a significantly adverse impact on the engineering performance on the soil subgrade,therefore, it is necessary to understand the soil behaviors under the freeze thaw cycles for the future projects. The soil resistivity,as an intermediate quantity,can be quickly measured,which means it may be suitable for the index properties of soil performance under permafrost conditions.In this study, soil samples were experienced seven (7) freezethaw cycles.The resistivity and deformation of soil samples were measured in the entire process to establish relationships among various parameters It can be concluded that, after measuring the resistivity during freeze, the sample deformedonly slightly under the closed condition. Different sample of degrees of compaction haveresulted in different resistivity values.The maximum variation of sample resistivity changes linearly with temperature under the frizzed conditions. Related Articles | Metrics

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Water Absorption of Red Clay and its Influence on the Slaking Test ZHANG Binghui, XIE Yanhua, LIU Lei, LIU Baochen, ZENG Qingjian, XIAO Shide 2020, 34 (6):  732-735.  Abstract ( 391 )   Save During the red clay slaking, the weight increase during the water absorption will affect the accurate measurement the soil slaking property. In order to study the effect of water absorption and weight increase on the slaking of the red clay, water absorption tests were conducted under different water temperatures. The experimental results show that the water absorption will affect the slaking measurement results, and the samples with low water content will have negative slaking. The water absorption will result in a low average slaking rate. The water absorption of the red clay sample is affected by the moisture content of the soil and the water temperature. The water absorption rate and the total water absorption increase with the increase of temperature; The water absorption rate and the total water absorption increase with the decrease of soil moisture content; When the moisture content of the sample reaches 18%, the influence of water absorption on the slaking of the red clay could not be measured. Related Articles | Metrics

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Permeability of Structural Clay of Zhanjiang Formation WANG Lingling, FENG Zhiguo 2020, 34 (6):  736-739.  Abstract ( 310 )   Save During the consolidation of soil samples, the soil is affected by surrounding stresses, the pore water is dissipated, the pore voidsare gradually reduced, and the relative positions of soil particles are also rearranged. Some large pore voids are closed by the compression, and the connections among the particles gradually reduces the permeability. With the increase of the stress around on the soil sample, the density of the soil becomes larger, and the relative strain of the soil is smaller. For the structural clay samples of Zhanjiang Formation, when the consolidation pressure increases to a certain value, the structure of the soil sample is destroyed, and then the structure is solidified. Within this pressure region, the pressurized permeability coefficient is in a state of random change, and the porosity ratio, pressure series and density of soil samples are independent. Related Articles | Metrics

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Influence of Particle Shape on the Direct Shear Properties of Coarse Sand Samples ZHAO Shuhui, WEI Houzheng, WU Yongjie, WANG Rui, 2020, 34 (6):  740-744.  Abstract ( 317 )   Save The change of physical and mechanical properties of the geomaterials can be attributed to the change of microstructures of materials. Three soil samples with different grain shapes were studied by a grain shape scanning device. The influence of the grain shape on the shear strength of coarse sand samples are evaluated by the direct shear tests. The results indicate that, based on their sensitivity, the ranking of the four grain shape parameters is: length to width ratio>flatness ratio>wearing ratio>roundness ratio. When the shape of the coarse sand is more “regular”, the smaller of the internal friction angle for the particle rearrangement. As a result, the internal friction angle with the regularity of the grain particles will reduce. After reaching the peak shear strength, the sliding frictions among particles is smaller for the more “regular shaped” particles and then the smaller residual internal friction angle. Related Articles | Metrics

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Summary of the Soil Laboratory Test Results in Urban Mudanjiang City WANG Jianwei, TONG Zhiqiang, SONG Linxu, GAO Bo, SONG Lidong 2020, 34 (6):  745-749.  Abstract ( 290 )   Save This paper summaries statistical laboratory test results on fine grained soil samples from the urban Mudanjiang City. The correlations between physical indices and mechanical properties of fine grain soils are statistically analyzed by using regression method. Results show that the physical indices of finegrained soil samples from urban city, such as density (ρ), moisture content (ω) and liquid limit (wL) are within in a predictable range. The value of these physical characteristics of fine-grained soil could be related to the range of soil type and their mechanical properties. There is obvious correlation existed between physical indices and mechanical properties. The compression modulus (ES) and shear strength values are positively correlated with density (ρ), and negatively correlated with moisture content (ω). Related Articles | Metrics

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Application of MultiBeam Sounding System in an Underwater Marine Slope Stability Inspection fora SeaCrossing Bridge Foundation YAO Wenjie, WANG Huajun, MA Yuquan 2020, 34 (6):  750-752.  Abstract ( 406 )   Save In this paper, a multibeam bathymetric system with wide coverage and high resolution was used to obtain detailed bathymetric data of an underwater marine slope near foundations of Xihoumen Bridge. The system provides the basic topographic data for the further analysis and evaluation of the overall stability of the marine slope by generating underwater topographic map and analyzing characteristics of the seabed topography and geomorphology. Through the establishment of threedimensional point cloud model, the shape, gradient, topographic fluctuation and detailed to pographic features of underwater coastal slope can be determined quickly and intuitively.Through judging whether there are some unfavorable phenomena such as erosion and scour, the stability inspection of underwater marine slope near the bridge foundation could be conducted. The success of the multibeam sounding system application in the inspection of this underwater marine slope near the bridge foundation could be referenced for similar projects in the future. Related Articles | Metrics

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Construction Monitoring of Surcharge Combined with Vacuum Preloading Method in Highway Embankment over Soft Soils LI Xianxing, FAN Jingcheng, YIN Beibei, ZHANG Hao, ZHANG Xue 2020, 34 (6):  753-756.  Abstract ( 289 )   Save The impact of highway embankment over soft soils on the entire highway construction project is obvious. Inappropriately treated soft soil might result in a series unfavorable issues that affecting the performance during the construction as well as in service life of the highway embankments. As the surcharge load in the combination of surcharge and vacuum preloading methods, the soil can also serve as part of the embankment fill and no need of significant unloading. Therefore, both the construction schedule and cost can be saved. This paper presents a case history of an expressway project. The construction monitoring results for the combined surcharge and vacuum preloading methods are compared with the estimated results. It is proved that this combination is effective for the soft soil improvement. Related Articles | Metrics