论文部分内容阅读
自钻式旁压试验(SBPT)因其扰动小、测试深度大、可以获得应力-应变、超孔隙水压力-时间等数据,在确定地基土性参数和地基承载力上有广阔的应用前景。然而由于用以解释SBPT的柱孔扩张理论(Gibson解)所采用的平面应变假设与实际旁压腔几何特征存在差异,导致试验所确定的黏土不排水剪切强度su与其他原位试验或室内试验结果存在差别。针对旁压腔几何尺寸及应变区间的选择对确定su的影响,基于修正剑桥模型,采用低渗透系数控制加载过程中不排水条件,利用有限元法模拟SBPT,建议了不同应力历史下确定su的应变区间,并给出考虑几何尺寸影响时相应应变区间上su的修正系数。
Because of its small perturbation and large test depth, SBPT can obtain the data of stress-strain, excess pore water pressure-time and so on. It has broad application prospect in determining soil parameters and foundation bearing capacity. However, due to the difference between the plane strain assumption used to explain the column expansion theory of SBPT (Gibson solution) and the actual pressure chamber geometry, the undrained clay shear strength, su, The test results are different. According to the modified Cambridge model, the low permeability coefficient was used to control the undrained condition in the loading process. The finite element method was used to simulate the SBPT. It is suggested that su be determined under different stress history Strain interval, and gives the correction factor of su in the corresponding strain interval when considering the influence of geometric size.