Bearing capacity of foundation on slope determined by energy dissipation method and model experiments

To determine the ultimate bearing capacity of foundations on sloping ground surface in practice, energy dissipation method was used to formulate the bearing capacity as programming problem, and full-scale model experiments were investigated to analyze the performance of the soil slopes loaded by a strip footing in laboratory. The soil failure is governed by a linear Mohr-Coulomb yield criterion, and soil deformation follows an associated flow rule. Based on the energy dissipation method of plastic mechanics, a multi-wedge translational failure mechanism was employed to obtain the three bearing capacity factors related to cohesion, equivalent surcharge load and the unit gravity for various slope inclination angles. Numerical results were compared with those of the published solutions using finite element method and those of model experiments. The bearing capacity factors were presented in the form of design charts for practical use in engineering. The results show that limit analysis solutions approximate to those of model tests, and that the energy dissipation method is effective to estimate bearing capacity of soil slope.     

考虑体变与大变形时高应力砂性土扩孔问题能量分析方法比较

根据圆孔扩张过程中塑性区土体在孔扩压力作用下的应力–应变–体变关系、扩孔过程中的能量守恒原理、非相关联流动准则以及莫尔–库仑破坏准则,分别给出考虑体变守恒和大变形规律2种条件下砂性土圆孔扩张问题的极限扩孔压力计算公式.实测结果与2种理论结算结果的对比分析表明:考虑大变形时的理论成果与实际情况更加吻合,因此该方法具有一定的工程应用价值,可以用于砂性土的极限扩孔压力预估.而且,由于剪胀的影响,砂性土的极限扩孔压力与剪切模量和剪胀系数的总体关系是非线性的先减后增关系.     

盾构注浆荷载作用下带榫管片水平轴线偏移量计算方法研究

为探明隧道盾构注浆荷载作用引起带榫管片水平轴线偏移规律，以小曲率半径盾构隧道为例，分析壁后注浆引起管片上浮的诱因，考虑管片环“椭圆化”变形、纵向连接螺栓预应力、环缝影响范围和横向刚度等综合因素的影响，建立榫杆连接条件下带榫环缝的管片单元纵向等效抗弯刚度有效率计算式，并通过计算盾构注浆荷载作用下带榫管片的静态和动态上浮力，构建盾构注浆荷载作用下带榫管片上浮力计算表达式，由此分析小曲率半径隧道盾构注浆荷载作用下带榫管片受力情况及其在文克尔弹性地基梁假定条件下受上浮力作用的挠曲变形规律，建立盾构注浆荷载作用下带榫管片水平轴线偏移量计算方法，并依托实际工程加以验证。结果表明：该文理论值与模拟值和监测值均拟合良好，该文计算方法具有良好的工程适用性，可为盾构隧道工程及其类似工程中注浆荷载作用下管片偏移及错台问题提供有效的理论指导。