Load-bearing behavior and interaction of rigid inclusion systems with granular load transfer platforms

刚性包裹体在德国是一种较新的土壤改良方法。刚性夹杂与传统桩基的本质区别在于柱上方的荷载传递平台（LTP）。柱、柱之间的土壤和LTP相互作用，形成一个组合的整体系统，决定了承载性能。本课题研究的重点是湿砂浆柱类型。在部分或全位移螺旋钻穿透之后，注入混凝土。柱的直径通常约为。20至40厘米。它们安装在中心距离为3D至5D的网格中。刚性夹杂系统的承载性能尚未完全理解，设计所基于的模型是简化的方法。由于网格状安装过程引起的土壤状态参数变化的影响尚未量化艾德。此外，循环荷载对荷载传递的影响和LTP中的阻尼效应还没有得到充分的研究。因此，本研究项目的主要目的是阐明刚性夹杂系统的承载性能，考虑安装效应，群体效应和土，柱，荷载传递层和基础之间的相互作用在静态单调和循环荷载下。为此，数值模拟进行了补充和模型试验验证。对于数值计算，使用连续介质模型。用有限元法求解了相应的方程。为此，应用CEL方法，该方法已在钻井过程模拟的初步研究中得到证明。

Rigid inclusions, are a relatively new method for soil improvement in Germany. An essential difference between rigid inclusions and conventional pile foundations is the load transfer platform (LTP) above the columns. The columns, the soil between the columns and the LTP interact and form a combined overall system which determines the load bearing behavior. The research project is focused on the type of wet mortar column. After the penetration of the partial or full displacement auger the concrete is injected. The diameter of the columns is usually approx. 20 to 40 cm. They are installed in a grid with a centre to centre distance of 3D to 5D. The load-bearing behavior of rigid inclusion systems is not yet fully understood and the models on which the design is based are simplified approaches. The influence of a change in the soil state parameters due to the grid-shaped installation process is not yet quantified. Furthermore, the influence of cyclic loading on the load transfer and the arching effect in the LTP has not been sufficiently researched. The main objective of the research project is therefore to clarify the load-bearing behavior of rigid inclusion systems, taking the installation effect, the group effect and the interaction between soil, column, load transfer layer and foundation under static monotonic and cyclic loading into account. For this purpose, numerical simulations are carried out, which are supplemented and validated by model tests. For the numerical calculations, continuum models are used. The corresponding equations are solved with FEM. For this purpose, the CEL approach is applied, which has proven itself in the preliminary investigations for the simulation of the drilling process.