Based on the fictitious soil pile model, the effect of sediment on the vertical dynamic impedance of rock-socketed pile with large diameter was theoretically studied by means of Laplace transform technique and impedan...Based on the fictitious soil pile model, the effect of sediment on the vertical dynamic impedance of rock-socketed pile with large diameter was theoretically studied by means of Laplace transform technique and impedance function transfer method. Firstly, the sediment under rock-socketed pile was assumed to be fictitious soil pile with the same sectional area. The Rayleigh-Love rode model was used to simulate the rock-socketed pile and the fictitious soil pile with the consideration of the lateral inertial effect of large-diameter pile. The layered surrounding soils and bedrock were modeled by the plane strain model. Then, by virtue of the initial conditions and boundary conditions of the soil pile system, the analytical solution of the vertical dynamic impedance at the head of rock-socketed pile was derived for the arbitrary excitation acting on the pile head. Lastly, based on the presented analytical solution, the effect of sediment properties, bedrock property and lateral inertial effect on the vertical dynamic impedance at rock-socketed pile head were investigated in detail. It is shown that the sediment properties have significant effect on the vertical dynamic impedance at the rock-socketed pile head. The ability of soil-pile system to resist dynamic vertical deformation is weakened with the increase of sediment thickness, but amplified with the increase of shear wave velocity of sediment. The ability of soil pile system to resist dynamic vertical deformation is amplified with the bedrock property improving, but the ability of soil-pile system to resist vertical vibration is weakened with the improvement of bedrock property.展开更多
Piles socketed in soft rock were traditionally regarded as end bearing piles, and the loads transferred from superstructure were assumed in design to be shouldered totally by the piles. This paper was designated to ...Piles socketed in soft rock were traditionally regarded as end bearing piles, and the loads transferred from superstructure were assumed in design to be shouldered totally by the piles. This paper was designated to deal with the interaction between the piles socketed in weak rock and surrounding soil through field measurement. The pile head reaction and ground pressure under piled raft foundation were monitored, respectively. The analysis of the data measured in situ shows the characteristics of the pile embedded in weak rock are similar to that of friction pile to some extent. The rock socketed pile, together with the surrounding soil, shoulders the weight of the superstructure. It is suggested that soil bearing should be considered in designing the soft rock socketed piles, which can make the design more economical.展开更多
A new comprehensive set of data（n = 178） is compiled by adding a data set（n = 72） collected by Arioglu et al.（2007） to the data set（n = 106） presented in Rezazadeh and Eslami（2017）. Then, the compiled data s...A new comprehensive set of data（n = 178） is compiled by adding a data set（n = 72） collected by Arioglu et al.（2007） to the data set（n = 106） presented in Rezazadeh and Eslami（2017）. Then, the compiled data set is evaluated regardless of the variation in lithology/strength. The proposed empirical equation in this study comprises a wider range of uniaxial compressive strength（UCS）（0.15 MPa 〈 σ_（rc） 〈156 MPa） and various rock types. Rock mass cuttability index（RMCI） is correlated with shaft resistance（r_s） to predict the shaft resistance of rock-socketed piles. The prediction capacity of the RMCI versus r_s equation is also found to be in a fair good agreement with the presented data in Rezazadeh and Eslami（2017）. Since the RMCI is a promising parameter in the prediction of shaft resistance, the researchers in the rock-socketed pile design area should consider this parameter in the further investigations.展开更多
为研究干湿循环作用下钢-土界面剪切特性对钢护筒嵌岩桩周土软化变形规律的影响,通过改进的室内直剪试验,设计一定含水率、干密度、级配的初始试样,进行了初始状态和4次干湿循环共5组工况的试验,依次在50 k Pa、100 k Pa、150 k Pa和200...为研究干湿循环作用下钢-土界面剪切特性对钢护筒嵌岩桩周土软化变形规律的影响,通过改进的室内直剪试验,设计一定含水率、干密度、级配的初始试样,进行了初始状态和4次干湿循环共5组工况的试验,依次在50 k Pa、100 k Pa、150 k Pa和200 k Pa这4种法向应力条件下进行钢-土界面和土体本身的剪切试验。试验结果表明:干湿循环对土体本身的影响大于对钢土界面抗剪强度的影响;钢-土界面剪切过程中应力-应变关系呈弹塑性变化,没有出现应变软化现象;钢-土界面和土体本身摩擦角变化不大,而黏结力呈先增大后减小的变化趋势。展开更多
基金Projects(51109084/E09070151308234/E08061) supported by the National Natural Science Foundation of China+1 种基金Project(2013J05079) supported by the Natural Science Foundation of Fujian Province,ChinaProject(Z012002) supported by the Open Research Fund of State Key Laboratory of Geomechanics and Geotechnical Engineering(Institute of Rock and Soil Mechanics,Chinese Academy of Sciences),China
文摘Based on the fictitious soil pile model, the effect of sediment on the vertical dynamic impedance of rock-socketed pile with large diameter was theoretically studied by means of Laplace transform technique and impedance function transfer method. Firstly, the sediment under rock-socketed pile was assumed to be fictitious soil pile with the same sectional area. The Rayleigh-Love rode model was used to simulate the rock-socketed pile and the fictitious soil pile with the consideration of the lateral inertial effect of large-diameter pile. The layered surrounding soils and bedrock were modeled by the plane strain model. Then, by virtue of the initial conditions and boundary conditions of the soil pile system, the analytical solution of the vertical dynamic impedance at the head of rock-socketed pile was derived for the arbitrary excitation acting on the pile head. Lastly, based on the presented analytical solution, the effect of sediment properties, bedrock property and lateral inertial effect on the vertical dynamic impedance at rock-socketed pile head were investigated in detail. It is shown that the sediment properties have significant effect on the vertical dynamic impedance at the rock-socketed pile head. The ability of soil-pile system to resist dynamic vertical deformation is weakened with the increase of sediment thickness, but amplified with the increase of shear wave velocity of sediment. The ability of soil pile system to resist dynamic vertical deformation is amplified with the bedrock property improving, but the ability of soil-pile system to resist vertical vibration is weakened with the improvement of bedrock property.
文摘Piles socketed in soft rock were traditionally regarded as end bearing piles, and the loads transferred from superstructure were assumed in design to be shouldered totally by the piles. This paper was designated to deal with the interaction between the piles socketed in weak rock and surrounding soil through field measurement. The pile head reaction and ground pressure under piled raft foundation were monitored, respectively. The analysis of the data measured in situ shows the characteristics of the pile embedded in weak rock are similar to that of friction pile to some extent. The rock socketed pile, together with the surrounding soil, shoulders the weight of the superstructure. It is suggested that soil bearing should be considered in designing the soft rock socketed piles, which can make the design more economical.
基金support of Yapi Merkezi Construction and Industry Inc.,Istanbul,Turkey
文摘A new comprehensive set of data（n = 178） is compiled by adding a data set（n = 72） collected by Arioglu et al.（2007） to the data set（n = 106） presented in Rezazadeh and Eslami（2017）. Then, the compiled data set is evaluated regardless of the variation in lithology/strength. The proposed empirical equation in this study comprises a wider range of uniaxial compressive strength（UCS）（0.15 MPa 〈 σ_（rc） 〈156 MPa） and various rock types. Rock mass cuttability index（RMCI） is correlated with shaft resistance（r_s） to predict the shaft resistance of rock-socketed piles. The prediction capacity of the RMCI versus r_s equation is also found to be in a fair good agreement with the presented data in Rezazadeh and Eslami（2017）. Since the RMCI is a promising parameter in the prediction of shaft resistance, the researchers in the rock-socketed pile design area should consider this parameter in the further investigations.
文摘为研究干湿循环作用下钢-土界面剪切特性对钢护筒嵌岩桩周土软化变形规律的影响,通过改进的室内直剪试验,设计一定含水率、干密度、级配的初始试样,进行了初始状态和4次干湿循环共5组工况的试验,依次在50 k Pa、100 k Pa、150 k Pa和200 k Pa这4种法向应力条件下进行钢-土界面和土体本身的剪切试验。试验结果表明:干湿循环对土体本身的影响大于对钢土界面抗剪强度的影响;钢-土界面剪切过程中应力-应变关系呈弹塑性变化,没有出现应变软化现象;钢-土界面和土体本身摩擦角变化不大,而黏结力呈先增大后减小的变化趋势。
