地基排水控制法的沉降和孔压数值分析

地基排水控制法是一种通过加速施工期间地基超孔压消散并限制工程运营期间地基的超孔压消散，一方面促进沉降在施工期间尽可能多地发生，另一方面使工程使用年限内的工后沉降发生的速度尽可能降低，从而达到最大限度地控制地基工后沉降目的的新型地基处理方法。采用基于六面体孔压单元及塑料排水板线性单元等三维有限元技术，分析了排水控制法处理后地基的工后沉降与竖向防渗帷幕及塑料排水板深度的关系、工后沉降和超孔压随时间和空间的分布规律，得出了排水控制法具有以相对低廉的工程造价，在较短的工期内获得工后沉降为0的特殊处理效果，可以设置较浅的竖向防渗帷幕深度和较深的塑料排水板深度来寻求较高的性价比，工程运营期间密封区域以内超孔压上升导致的有效应力减小是排水控制法减小地基工后沉降的重要原因等结论。

Numerical analysis of settlement and pore pressure of drainage controlling ground treatment method

The drainage controlling ground treatment method(DCM) is a new ground treatment method which accelerates the pore pressure dissipation to accelerate settlement as fast as possible during construction period and decelerates ground post-construction settlement to control the post-construction settlement furthest by confining the excess pore pressure dissipation of the ground during the operation period. Finite element method technique like hexahedron pore fluid element and linear prefabricated vertical drainage element is adopted. The relationship between ground post-construction settlement and the depth of anti-seepage curtain and prefabricated vertical drainage is revealed. The regularities of the distribution of the ground post-construction settlement and the excess pore pressure with time and space are also revealed. Conclusion is drawn as follows: The DCM has the special effect of achieving 0 post-construction settlement with relative low engineering costs and relative short duration; high performance price ratio can be pursued by setting relative shallow anti-seepage curtain and relative deep prefabricated vertical drainage; decrease of the effective stress during operation caused by increase of the excess pore pressure in the sealed scope is the main reason of DCM decreasing the post-construction settlement.