东北寒冷地区塑料排水板法处理软土路基的理论分析

在道路工程建设中经常碰到软土路基处理的情况，塑料排水板是处理软土路基的有效方法之一。塑料排水板处理软土路基，可缩短软土层的压缩排水时间和路基沉降时间，加快软土路基的固结速度，提高路基承载力，减小路基的工后沉降。从理论上对打塑料排水板处理软土路基前后的效果进行分析，反映出塑料排水板处理软土路基的有效性，为进一步研究分析地基压缩沉降和固结稳定提供了客观依据。     

超载预压处理深厚软土地基的现场试验研究

通过收集和整理厦门某港区试验区的长期监测数据,总结分析软土地基在超压荷载作用下的沉降变化规律、分层沉降变化规律;设置不同工况检验塑料排水板的打设和加载方式对沉降的影响;同时对超载预压法处理深厚软土地基的加固效果作出评价.试验表明：预压荷载越大,最大固结沉降速率线性增大;预压阶段,发生沉降的主要是打设有塑料排水板的软土区域,软土层的沉降占累计总沉降的70％左右;塑料排水板的打设对超载预压法处理深厚软土地基具有显著的加速效果.     

超载预压塑料排水板加固软土地基试验研究

文章以我国东部沿海某新建机场地基处理工程为背景,通过动态监测加固地基的地表沉降、差异沉降、分层沉降、侧向变形、地下水位及孔隙水压力,探讨超载预压塑料排水板加固软土地基的变形规律及效果,为类似工程的优化设计和安全施工提供科学依据。     

Experimental and theoretical studies on the lateral collapse of mechanically lined pipes

The mechanically lined pipe, which consists of a thin non-corrosive liner and a carbon steel pipe, is an economical way to transport acidic fluid in offshore applications. However, it is prone to lateral loading and potentially develops plastic collapse and liner separation during the operational stage. The present study examines its crushing performance using small-scale 2-inch lined pipes manufactured by a customized hydroforming facility. The lined pipes comprised a seamless GB45 carbon steel tube and a grade T2 copper liner. Four ring specimens extracted from lined pipes and two single-layer rings were crushed on a universal testing machine in a quasi-static manner. The tube was found to develop an ovalized shape initially and then changed into a "∞" shape in the end. The carrier and liner were found to stay together throughout the crushing process, with slight liner separation taking place. The manufacture and lateral collapse processes were also reproduced with finite element models and nonlinear analytical formulation. The analytical model was established based on the principle of virtual work and nonlinear ring theory, assuming small strain and finite rotation. It showed that the analytical and numerical simulation results agreed with the experimental results. The influence of major parameters of the problem was also studied based on the full-scale lined pipe. Amongst other findings, manufacture-related plastic hardening is shown to affect the load-carrying capacity and the growth of separation during lateral collapse.