Soil deformations close to retaining walls due to vibration excitations

本分项研究在高周反复荷载作用下饱和土体中的堆积现象，这种堆积现象是由土工施工过程引起的，例如在挡土墙附近进行振动桩打桩。根据现场条件(土壤类型、密度、饱和度、排水、渗透性)的不同，不同的安装过程或方法可能会导致有效压力降低、土壤液化、蠕变行为，从而导致大变形。还应考虑施工构件的安装顺序及其对邻近结构变形的影响。这项研究将包括循环载荷动态边值问题的数值解，目的是找出振幅场、有效应力的永久变化和由此产生的变形。最后，它的目的是提出一种预测变形的方法，作为实际建议的基础。

The present subproject deals with accumulation phenomena in saturated soils during high-cycle load-ing caused by geotechnical construction processes such as the vibratory pile driving in the vicinity of a retaining wall. Depending on the in-situ conditions (soil type, density, degree of saturation, drainage, permeability), various installation processes or methods can lead to the reduction of the effective pressure, soil liquefaction, creep-like behaviour and, as a consequence, to large deformations. The sequence of the installation of construction elements and their effect on the deformation of the neighbouring structures should also be taken into account. The study will consist in the numerical solution of dynamic boundary value problems for cyclic loading with the aim of finding the amplitude fields, the permanent changes in the effective stresses and the resulting deformations. Eventually, it is intended to suggest a method of prediction of deformations as a basis for practical recommendations.