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20 June 2014, Volume 28 Issue 3 Previous Issue    Next Issue

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Well Point Dewatering Applications in the Deep Excavation of anExtra HighRise Building HUANG Ming 2014, 28 (3):  1-3.  Abstract ( 1445 )   Save With an increase amount of high and extra highrise buildings, the well point dewatering technics is widely utilized in the construction in Nantong area. In some cases, the number and depth of the well points in were determined by the conventional dewatering analysis, but they were unsuccessful since the soil stratigraphy impact on the dewatering was not considered. This paper presents the suggestions and consideration in the deep dewatering well design and construction. Related Articles | Metrics

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Dewatering Design and Construction in Dual Stratigraphy Aquifers DING Xiaohong 2014, 28 (3):  4-6.  Abstract ( 1486 )   Save The dewatering design in the deep excavations in the urban area has an important role of minimizing the disturbance of the adjacent environment. To achieve this goal, the dewatering design should be based on the different underground soil conditions. For shallow groundwater depositions, the conventional method is to prevent the infiltration of surface water and to drain the shallow water tables. The well points are usually used to control the deep pressurized aquifers. Monitoring is an important measure in the ground surface deformation induced by the dewatering operation. The design requirements at every aspects of each element: installation of the borehole, casing lowering, filling of the filtering material, well washing and preliminary dewatering testing as well as dewatering operation, should be closely followed. Related Articles | Metrics

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Improvement in Shielded Excavation of Tunnels in Rounded Gravels KE Shumei 2014, 28 (3):  7-10.  Abstract ( 1496 )   Save The end improvement of the shielded tunnel excavation is an important procedure in the initial and arrival of the shielded tunnel. For the tunnel excavation in rounded gravel soils, there are some special aspects of this technology are discussed. The case history of slurry wall combined with sleeve valve pipe grout method to improve the end of the shielded tunnel is presented in this paper. Related Articles | Metrics

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Cast-In-Place Pile Defects and Mitigations in a Deep Excavation Supporting System HU Jianwei, DENG Shaolin, DENG Xuedeng 2014, 28 (3):  11-12.  Abstract ( 1793 )   Save The long flight auger with super flow concreting method was used in the installation of the supporting system of a deep excavation in soft soils. The defects of the castinpace piles and their mitigations are also presented. Increasing the soldier pile spacing, improving the cast in place pile installation procedure as well as the pile integrity testing are the major components of a successful long flight auger with super flow concreting method application in the soft soils. Related Articles | Metrics

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The Analysis of the Main Structure of Gangxia North Station of Shenzhen Metro LI Juhong 2014, 28 (3):  13-17.  Abstract ( 1746 )   Save In order to minimize the limitation of the conventional simplified plane analysis method used for the structural analysis of metro station structures, the three dimensional structure analysis on a typical segment of the Xiagang North metro station main structure by using ANSYS 13.0. The stress characteristics during the construction and the in the normal operation of the main structures are analyzed. The results indicate that, each floor slab has bidirectional positive bending moments and the side walls have obvious force acting on them. The three dimensional analysis has the advantages over the conventional plane analysis method by considering the effect of all structural elements. In the condition of a void in the middle of the slab, the threedimensional analysis method can consider the effect of the void, which the conventional method could not. The analysis results also indicate the most unfavorable condition is when the station is under the normal operation conditions. Related Articles | Metrics

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Comparative Analysis of the Dynamic Characteristics of DK1252 ApproachCulvert in WuhanGuangzhou High Speed Rail Pan Ying 2014, 28 (3):  18-22.  Abstract ( 1338 )   Save This paper presents the three dimensional dynamic analysis of traintrack system in a transition zone over culverts in the WuhanGuangzhou high speed rail project. The dynamic response of the subgrade of the transition zone under an operational train speed of 350 km/h is studied. The following results are observed: 1) The dynamic displacement, vibration velocity and acceleration of the soils particles in the vertical direction at both the top and the bottom of the subgrade have minimum values at the crown of culverts. A rapid increase of these values can be found at the culvert sides. The dynamic stress distributions are at the opposite of the trend: It reaches the maximum value at the crown of culverts and creases towards the sides. 2): The degradation of the dynamic stress has an exponential relationship with depth and a plat pattern can be found at a depth of one meter below the ground. At a depth of three meters below the ground, the dynamic stress approaches a constant value. A rapid decease in the vibration acceleration can be found and the dynamic displacement, vibration velocity and dynamic stress have flatter reduction. The insitu monitoring results are similar to the numerical analysis results. Related Articles | Metrics

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Analysis of a Deep Excavation near an Active Shielded Metro Tunnel FANG Chengfei1, CHU Zhenhuan2 2014, 28 (3):  23-26.  Abstract ( 1741 )   Save Strict deformation control was applied to a deep excavation near an active shielded metro tunnel due to the safety concern of the metro operation. This paper presents the analytical results of this large depth deep excavation with a concentration on the important and difficult issues. Two different excavation support systems are proposed. The process of the excavation was simulated by using Finite Element Analysis considering the plane strain coupled with seepage. The final selected supporting system was based on the comparative studies of both systems. The predicted data are comparable with the observed data during the construction. Related Articles | Metrics

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Numerical Modeling and Monitoring of a Complicated Void Zone in Zijinshan GoldCopper Mine LAI Hongyuan 2014, 28 (3):  27-32.  Abstract ( 1751 )   Save After years of the underground mining in Zijinshan GoldCopper Mine, mining voids have developed directly underneath the production zone. Mining voids are the safety hazard to the open pit mining operation. This paper presents the stability numerical analysis and insitu monitoring results. The mining voids can be characterized from the stability analysis and monitoring therefore, these activities provide a safety guide to the open pit mining operation. Related Articles | Metrics

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Geological Hazards Prevention Methods Optimization in a Scenic Project LI Qingwei, HU Jianwei, LIU Lei 2014, 28 (3):  33-34.  Abstract ( 1589 )   Save This paper characterizes the principles of the geological hazards prevention in a scenic project. The optimization process is performed on all feasible mitigation methods and the ground anchor with concrete grid beam method was selected. The effect of the selected method is verified throughout the insitu monitoring during the construction and the operation. Related Articles | Metrics

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No Column Canopy Underpinning Technique in a Metro Construction LIN Dong 2014, 28 (3):  35-37.  Abstract ( 1698 )   Save This paper presents a case study of the underpinning of a no column canopy in a regional metro construction. The selection of underpinning and passive underpinning systems, construction technique and monitoring are also introduced in the paper.[JP] Related Articles | Metrics

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Application of a Composite Grouting Paste in the Seepage Prevention in Sandy Gravel Soils LUO Huijun1, LIU Meng2 2014, 28 (3):  38-40.  Abstract ( 1572 )   Save The seepage prevention in the sandy gravel soils with large voids and high seepage rates is a challenge work in hydraulic projects. This paper summarizes various seepage prevention methods in sand gravel soils. Researches have been performed on the improvement of a composite grouting paste and its construction procedures. The grouting with this new composite material has been successfully applied on the seepage prevention work for the sandy gravel soils at the right embankment of Longfeng Hydraulic Power Generation Station, Jiangyou City of Sichuan Provence. Related Articles | Metrics

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Dam Shaped Bamboo Soil Nails and Soldier Piles as Supports for Deep Excavations ZHOU Zhongjing 2014, 28 (3):  41-44.  Abstract ( 1730 )   Save This paper presents an innovative deep excavation support system: "dam shaped bamboo soil nails and soldier piles for the excavation support". This method is replacing the high energy consumption steel reinforcement bars with environment friendly bamboo bars. The bamboo bars can also be used as soldiers in supporting the excavations. The dam shaped bamboo soil nail distribution can be used to replace the conventional soil nails with equal nail length or longer nails at top with shorter nails at bottom. The stressstrain analysis on bamboo bars, the insitu pull out tests and numerical analysis have been performed. It is concluded that the application of the bamboo bars in the deep excavation support is appropriate. The bamboo bar can also serve as a casing to guide the grout slurries to the greater depth of the nail; therefore, safety factors of the excavation supporting system can be enhanced. Related Articles | Metrics

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Case Study of a Slurry Wall Construction under Complicated Subsurface Conditions YAO Zhimin1, YANG Rui1,2, LIU Hao1, WANG Lili2 2014, 28 (3):  45-48.  Abstract ( 1751 )   Save The application of underground slurry wall in the deep excavation projects results in a better performance of excavation supporting system, especially, for deep excavations under the complicated subsurface conditions. In the practical applications, the slurry wall construction technique should allow slight modifications in order to fit for the specific subsurface conditions. The key as well as most difficult aspects of the slurry construction methods are introduced in this paper through a case history. The construction monitoring should be performed and the monitoring data should be processed so that the deformation of the slurry wall can be presented. The construction monitored data indicate that the application of slurry wall method in the deep excavation support is a success. Related Articles | Metrics

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A Cut Slope Stability Analysis at K331+332~+600 Left, Yi-Zhan Railway Line LI Shuiping 2014, 28 (3):  49-51.  Abstract ( 1525 )   Save A landslide occurred at a cut slope left side of YiyangZhanjiang Rail Line between Station K331+332 and +600. This paper characterizes the factors that might contribute to the sliding. The condition of the current slope is analyzed by the engineering geology and landslide transfer methods. It is concluded that the current slope is instable and mitigation is necessary. The remediation scheme is focused on a new retaining structure, diverting the surface runoff water as well as providing proper drainage to the groundwater. During the design, proper sampling and testing work are necessary in order to quantify the engineering properties of surrounding soil and rock materials. Related Articles | Metrics

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Design of a Rockfall Shelter for the Portal of Wangjiagou Tunnel in Xiang-Yu Line LI Yanxiang 2014, 28 (3):  52-55.  Abstract ( 1712 )   Save Rockfall is a serious geological hazard in railways in the mountainous areas and it is important to minimize the occurrence of the rockfall incidents since it has the characteristics of sudden and large damage scale. This paper presents the rockfall prevention project for a rockfall shelter for the portal of Wangjiagou Tunnel in XiangYu Railway Line. The design improvement was made on the rockfall shelter in an area with known rockfall hazards. The innovative design made an efficient rockfall shelter protecting both the existing railway line and the proposed line with a large distance. Related Articles | Metrics

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Ground Anchor Design for a Retaining Wall with Large Surcharges LIU Lin 2014, 28 (3):  56-58.  Abstract ( 1883 )   Save The flat area at the front tongue of a historical landslide site was selected to be a storage yard of sand and other coarse aggregate. The surcharge load might potentially result in the excessive compressive of the soil behind the wall and cause shear failure of the retaining wall. The ground anchored retaining with drainage and monitoring measures was selected as the design scheme. The stability analysis as well as the monitoring during the site operation indicates that the anchored retaining wall design was a success. Related Articles | Metrics

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Deformation Monitoring of Deep Excavation in Soft Soils with Different Supporting Structures ZANG Guangwen 2014, 28 (3):  59-61.  Abstract ( 2088 )   Save Due to the lack of available for the construction in urban area, large scale deep excavations in densely populated, closely adjacent to existing buildings and streets are common for the construction of metros, underground parking garages and underground shopping centers. To minimize the adverse effect induce from the deep excavation, the deformation of the supporting structures should be closely monitored. This paper summarizes the excavation supporting types encountered in the construction inspection projects and their deformation characteristics. Both advantages and disadvantages of each supporting type as well as their applicable conditions are introduced in the paper. Related Articles | Metrics

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Deep Excavation Support Using TRD Method HUANG Bingde 2014, 28 (3):  62-66.  Abstract ( 1835 )   Save As a new supporting system for the deep excavation, the shaped steel reinforced soil cement walls formed by Tren Cutting Remixing Deep Wall (TRD) Method have the characteristics of suitable for a wide range of soil conditions, uniform and homogenous wall shape, and well mechanical and seepage cutoff performance. This paper presents a case history of the first installation of TRD wall in the Shanghai and even the deltaic area of Yangtze River in the support of the deep excavation for Fengxian Small and Medium Enterprise (SME) Building. The technical details of the TRD method in the design and construction practice are introduced. Related Articles | Metrics

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Mechanical Properties of Prestressed Concrete under High Temperature TIE Guoguo, LIU Jizeng, XIAO Weidong 2014, 28 (3):  67-69.  Abstract ( 1301 )   Save With the raising of the quality of living standard, citizen's demand on the building environment is also increasingly higher. A residential complex having comfortable and cozy living space and available for different space combinations that can meet different requirements for the entertainment, home working and rest are getting more and more popular. Compared with the conventional concrete, the prestressed concrete has the advantages that cannot be replaced; therefore, it has been widely applied in the building construction. However, the high temperature has an adverse effect on the performance of the prestressed concrete. This paper summarizes the factors that might impact the properties of the prestressed concrete. Related Articles | Metrics

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Coupling mathematic model of stress-seepage-chemistry of tailings deformation ZHENG Xunzhen 2014, 28 (3):  70-72.  Abstract ( 1224 )   Save The mathematical deformation model of tailing deposits is established by using the relationships among the stress-porosity and fluid concentration. The characteristics of porosity change in the tailing deposits are based on the mechanical performance and the dynamic leaching test results. This coupled model tailing deposit model with the coupling of stress-seepage-chemical interactions is also consider the effect of acid solutions. Related Articles | Metrics

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Degree of Vacuum Change in a Vacuum Preloading with Surcharge Project XU Pingbo1, LI Chenglei2 2014, 28 (3):  73-75.  Abstract ( 1539 )   Save When using the vacuum preloading with surcharge method to improve the saturated peaty soils, the degree of vacuum underneath the membrane and its vertical delivering into the deeper layer are critical to the duration of the preloading and the result of the soil improvement. This paper presents a case history of using this method from the microscopic point of view. The degree of vacuum change with soil depth and factors that affecting the degree of vacuum in the soil are analyzed. It is concluded that the degree of vacuum change in the soil is a process of air particles moving from high density areas to low density areas. The peaty soil media has a strong damping effect to the air particles and the energy dissipation in this soil is strong. Under 20 meters below the ground, the degree of vacuum cannot be detected. The vacuum formed below the ground water line is formed by lowering the ground water table. Related Articles | Metrics

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Optimization of Geogrid Reinforced Slopes HUANG Wenbin1,2, CHEN Xiaoping1,2,CHANG Xuening3 2014, 28 (3):  76-80.  Abstract ( 1523 )   Save The optimization process can be applied into the reinforced soil slopes. This paper presents the analyses of several reinforced soil designs for the same slope based on the pullout test results and different limit equilibrium analysis methods. The optimized design that meets the stability is then selected. The results indicate that, the factor of safety obtained by improved Swedish method or Dutch Method have close results but both results are high than the original Swedish Method. The seismic and groundwater condition have large impact f the stability of the reinforced soil slopes. The Ministry of Water Resources suggested method has a prominent effect of the foundation stability of the reinforced soils. A reasonable reinforcement can be readily obtained. Full length distribution of geogrids is recommended when the groundwater table is high. The stability of doublelayer reinforcement is obviously higher than that of single layer but the stability is not a simple superimpose of two layers of reinforcement. The location has limited effects for single layer reinforcement. The cost reduction can be achieved by placing the single reinforcement at the middle portion of the slope. The further comparisons indicate that the potential failure plane will change before and after the geogrid reinforcement regardless of the reinforcement scheme. Related Articles | Metrics

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Numerical Simulation of Dawangou Tunnel Excavation Sequence by FLAC3D LEI Gang 2014, 28 (3):  81-83.  Abstract ( 1698 )   Save The tunnel excavation sequence has important impacts on the deformation of the surrounding rock mass and the later supporting procedure. This is especially true for the rock mass classified as IV and V. However, the analogy and insitu survey are the major ways to determine the excavation sequence and the optimized excavation sequence is not usually selected. The three dimensional numerical analysis using FLAC3D is performed on the Dawangou Tunnel excavation which different sequences can be simulated and the deformation of the surrounding rock mass, development of the plastic zones and the stress within the rock mass can be compared so that an optimized excavation can be determined. Related Articles | Metrics

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Application of GRA in a Deep Excavation Supported by Anchored Tangent Pile Walls XIAO Rongjun1，MA Wei1，HUA Yeshuang2，NING Wuchao3,SHI Hongyan2 2014, 28 (3):  84-86.  Abstract ( 1666 )   Save The stability of the deep excavation for the community service center of Guangzhou Wushan Avenue is comprehensively evaluated by using Gray Relation Analysis (GRA) method. The deep excavation is supported by anchored tangent pile walls. The entire excavation supporting system is divided into several sub units so that the representative factors that might impact the stability of the excavation can be evaluated. These seven (7) factors are: internal supporting type, stiffness of the supporting system, surcharge near the excavation (asymmetric loading condition), width of the berm in front of the excavation, time lapse between the excavation and internal bracing, amount over excavation, anchor installation quality. The comprehensive evaluation value numbers recommended from the back analysis of the case history of the deep excavation failures as well as the insitu monitoring data are used as the reference of the evaluation. This deep excavation site can be quantitatively classified into [JP2]three safety categories based on the GRA approach. The GRA approach provides a useful tool for the prediction of the excavation. Related Articles | Metrics

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Optimization of Pile Location for Landslide Mitigations Using MIDAS/GTS GUO Yaoxin 2014, 28 (3):  87-90.  Abstract ( 1877 )   Save One of the key issues of using pile for the landslide mitigation design is to optimize the location of piles in related to the slope. The parametric studies on the impact of the pile locations are performed using MIDAS/GTS with the popular strength reduction method. When the pile is located at the bottom of the slope, the factor of safety and the lateral deformation reach the minimum values. The maximum factor of safety and the maximum lateral deformation are obtained when piles are located in the middle of the slope. The optimized location should be in the middle portion of the slop. Related Articles | Metrics

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The Influence of Karst Factors on the Stress and Settlement of a Raft Foundation HE Minru1, TAN Yiping2 2014, 28 (3):  91-93.  Abstract ( 1792 )   Save The influence of karst factors on the stress and settlement of the raft foundation is presented through a three dimensional numerical analysis by using ANSYS software. The analysis considers the interactions between the superstructures and foundations. Different karst cavity depth, radius, shape, stiffness, Poisson's ratio and thickness are investigated and their influences on the stress and settlement distribution in the raft foundation are discussed. Related Articles | Metrics

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Numerical Analysis of the Deep Excavation near a Metro Tunnel JIANG Nanning 2014, 28 (3):  94-96.  Abstract ( 1599 )   Save The deep excavation near a metro tunnel will impact the performance of the tunnel itself whereas the tunnel will affect the deformation of the excavation support system. The three dimensional numerical analyses are performed on a deep excavation in Shanghai using FLAC3D in order to provide guidelines for the design construction and monitoring of the proposed project. The results indicate that, after the excavation, bottom heave and ground subsidence is observed. The maximum bottom heave is near the metro tunnel. The tunnel has a global lateral movement towards the excavated area with a nonuniform movement. Tension stress might exist at the top as well as at the bottom of the metro tunnel. Related Articles | Metrics

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Characterization of Rock Fissures by Packer Tests CAI Hairong1, ZHU Xuanjie1, CHEN Qinghua2 2014, 28 (3):  97-99.  Abstract ( 1573 )   Save This paper presents the packer test results at three locations for a tunnel project. The rock mass fissure is characterized by tested PQ curves.  The fissures in the rock mass and their openness, filling materials as well as their deformation under [JP2]the loading are extensively studied. The results are compared and verified with the rock cores and sonic wave velocity test results.[JP] Related Articles | Metrics

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Embankment Settlement Prediction through an Optimization Model DING Jianrong 2014, 28 (3):  100-102.  Abstract ( 1658 )   Save The settlement prediction through the observed settlement with time data have a wide application in the high speed rail embankment construction. The settlementtime relationship of an embankment is a reverse "S" shape. The conventional settlement prediction method using the observed data have the limitations from the model and from the sampling data. The predicted settlement can often not reflect the practical situation. An optimized model which combines the contribution of different reverse "S" shape models is proposed in this paper. Different weights are assigned to the different sample models through the optimization process. The settlement obtained through this method has a better prediction result and can be applied in the settlement prediction of high speed rail embankments. Related Articles | Metrics

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Analysis the Post Construction Settlement of a Metro Tunnel CHEN Xing 2014, 28 (3):  103-105.  Abstract ( 1593 )   Save In the metro construction practice, it is often required to predict the post construction settlement magnitude during the construction. A stable post construction settlement is critical for the scheduling of the equipment installation and others. Three methods are often used: theoretical method; empirical method; and numerical analysis method. This paper presents the results of all three methods. A decision of whether a stable post construction settlement can be obtained was made based on three settlement prediction results. Related Articles | Metrics

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Geotechnical Considerations in Near Shore Land Reclamation by Hydraulic Fill HAN Huiling，LIU Zhenwang,LI Guojie 2014, 28 (3):  106-109.  Abstract ( 1532 )   Save The hydraulic fill and reclamation is one of the important measures in the development of the coastal urban areas. This paper presents the geotechnical site investigation results of heavy equipment manufacturing facility reclamation through the hydraulic fill in Binhai District of Tianjin. Base on the characteristics of the proposed structures, foundation types and site conditions, the following investigation methods and insitu testing methods are used: undisturbed soil sampling; Standard Penetration Tests; shear wave velocity measurement; vane shear tests; plate loading tests at shallow depth as well as laboratory tests. The properties of dredged soils; liquefaction susceptible soils are evaluated. The seismic settlement potential of loose soils, negative skin friction of piles and pile group performance issues are also analyzed. The extensive evaluation and analysis data provide reliable geotechnical design parameters. Related Articles | Metrics

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The Influence of Vegetation Distribution on the Surface and Ground Water Resources in Jilin Provence JIANG Jinsheng1, XIAO Changlai2 2014, 28 (3):  110-113.  Abstract ( 1391 )   Save Throughout the correlations between the vegetation and the distribution of surface and ground water resources, this presents the impact of the vegetation on the water resources in Jilin Province. The role of vegetation in the hydrological cycles is also discussed. The interrelations between the vegetation and the water resource are presented from the microscopic point of view. The results indicate that a close relationship can be found between the vegetation and the distribution of the water resources in Jilin Province. As an important stage in the entire hydrological cycles, the vegetation is a controlling factor that affecting the distribution of the water resources. Trees can be planted in water scarce areas so that the water resources can be positively adjusted for the need of social and economic development. Related Articles | Metrics

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2D Finite Element Analysis of the Surcharged Slopes ZHANG Qiang 2014, 28 (3):  114-116.  Abstract ( 1554 )   Save The surcharge load acting on the crown of the slopes is one of the important trigger factors of the slope failures. A comparative slope study is performed with different intensity of the surcharge loads, different locations and loading length by using software GeoSlope. The results indicate that a stable slope can be obtained if the loads with different intensities are at least 5 meters away from the edge the top of slope. The factor of safety for the slope stability will reduce rapidly if the surcharge load is within 5 meters to the edge. Larger load results in a larger factor of safety reduction. Under the same load intensity, the length of the load has an insignificant impact on the slope stability. This 5 meter safety distance can serve a preliminary guide line for the fill embankment operation, temporary stocking construction materials and new structures near the slope. Related Articles | Metrics

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Application of Rock Mass Classification in Double Shield TBM Construction XI Zhuhui1, LU Chengbo1, WANG Yanxia2, ZHANG Yuelin2 2014, 28 (3):  117-119.  Abstract ( 1550 )   Save Based on the current code defined rock mass classification, a new classification method for a water tunnel excavation by using double shield TBM method is proposed in this paper. The new classification method considers the variation of the excavation parameters in the TBM; gap between the surrounding rock mass and the lining; quantity, shape and size of the excavated materials; [JP2]percentage of the of the structural plane to the machine broke rock fragments; ratio of the soft to hard rock fragments in the excavated materials. This new classification method was used in the Daban Water Diversion Tunnel excavation project. Related Articles | Metrics

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Research of Blasting for Highway Rock Cuts KONG Bang1,2, HUANG Huaixuan3, CHENG Kang4 2014, 28 (3):  120-122.  Abstract ( 1765 )   Save This paper summarizes the different blasting methods use in the highway rock cuts. It is suggested that the rock cut through blasting should consider the rock mass classification, topography and the adjacent environment so that the blasting design can be optimized. The highway rock mass classification method has been discussed. The presplit technique is appropriate for the hard rock mass, whereas, the smooth blasting with a protective layer is more applicable to the soft rock mass to avoid the adverse effect on the cut slope. The fly rock due to the blasting, vibration impact on the adjacent pedestrians and structures should also be controlled and mitigated. Related Articles | Metrics

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Numerical Study of a Soft Ground for Raw Material Stockyard Improved by Preloading TIAN Tian， OUYANG Xiaoliang, YU Huozhong 2014, 28 (3):  123-127.  Abstract ( 1925 )   Save Preloading is a common ground improvement method. The soft cohesive soils are improved by the dissipation of excess pore water pressures through the wick drain or sand/stone columns. The numerical analysis is performed on the preloading treatment of a soft ground for the riverside raw material stockyard of Shanghai Meishan Steel Company by using sand column method. The sand column is simplified as sand wall in the numerical model. The soil deformation and the pore water pressure distribution and development are simulated. The results indicate that the installation of the sand/gravel columns is in favorable to the dissipation of pore water pressures. Under loading stage, an obvious soft ground deformation can be found. At the end of each load stage, an approximate of 70% of the ultimate settlement can be achieved. After that, the deformation rate is slow and is approaching to a stable status. It is concluded that a safe operation can be achieved. Related Articles | Metrics

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Ground Subsidence Mechanism and Mitigation Methods a Salt Solution Mining YANG Changlai1, KONG Junfeng2, LIU Wei3 2014, 28 (3):  128-131.  Abstract ( 1439 )   Save The ground subsidence is a common geology hazard in the salt solution mines. The salt solution mine has the characteristics of sudden collapse, large scale and long duration of damages. This paper summarizes typical ground subsidence cases in the last decades. All of the subsidence can be classified into three categories: Collapse caused by the cavity instability; Fault activation induced by the brine and groundwater corroding; Bearing capacity failure in the overlying rock mass due to the erosion damage. Factors that might induce the damage and their interrelationships are discussed and recommendation and suggestions are also proposed for the geological investigation as well as the mine shaft design and construction aspects. Related Articles | Metrics

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Uncertainties in the Embankment Settlement Predictions LI Jie 2014, 28 (3):  132-134.  Abstract ( 1165 )   Save The analysis and prediction of settlement is one of the key issues in the foundation design practice. In many cases the settlement values from the theoretical analysis and the monitoring results are often not even close. Therefore, it is important to monitor the embankment settlement during the construction, and the embankment filling rate should be controlled by the settlement rate so that the safety of the embankment can be assured during the construction. The post construction settlement magnitude can also be predicted and mitigated based on the measured settlement during the construction. However, there are uncertainties in the settlement model parameters, it is more appropriate to describe the settlement pattern with probability and probability distribution methods. The parameters are described as random variables and the model is established based on the Bayesian theory using WinBUGS software in the time domain. The prediction results are compared with the observed values. It is concluded that this method is a reliable method. Related Articles | Metrics

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Unit Weight Measurement with Water Replacement in the Quality Control of Compaction of  Concrete Faced Rock Fill Dams ZHOU Enfei, CHEN Binghui, WANG Hainan 2014, 28 (3):  135-137.  Abstract ( 1229 )   Save This paper briefly describes and analyzes the process of water replacement method in unit weight testing of compacted fill materials in the construction quality control of concrete faced rock fill dams. Both advantages and disadvantage aspects of the of this testing methods are discuss in order to improve the accuracy of this test. Related Articles | Metrics

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Application of Blasting by Hydraulic Pressure and Water Seal in the Highway Tunnel Excavation HUANG Huaixuan1, CHENG Kang2 2014, 28 (3):  138-140.  Abstract ( 1562 )   Save Large amount of dusts and poisonous gases generated during the excavation of highway tunnels have a significant adverse impact on the safety d heath of the tunnel construction personnel. This paper presents the results of using water bags as sealing of the lasting holes. The water fog generate from the blasting dilutes and absorbs the dusts and gases. Different locations of the water bags in the bore holes are tested and their effects are compared: bottom, bottom & top, and middle & top. All results show that the water bags are effective in dust and poisonous gas reduction. The most effective water bags locations are middle and top of the bore hole, where the dust reduction is between 30% and 35% and the blasting holes has a 4 to 9% improvement in the utilization. Related Articles | Metrics

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Experimental Relationship between Displacement and Earth Pressures onRigid Retaining Walls HE Xingliang 2014, 28 (3):  141-144.  Abstract ( 1700 )   Save This paper presents the research results of the rigid retaining wall displacement on the magnitude of earth pressures on the wall. Under the laboratory model testing conditions, the value of earth pressures are measured with different rotational displacement around the bottom of the model wall. The earth pressure contour lines are plotted. The relationship between the earth pressure and the wall rotational displacement is compared. Related Articles | Metrics