土工格栅老化对双向复合地基性状影响的室内模型试验

Indoop Model Experiment of the Influence of Geogrid Aging on Bidirectional Reinforced Composite Foundation

为研究土工格栅老化时长对双向复合地基性状影响的规律,对土工格栅进行光氧、热氧老化,选用不同老化时长的土工格栅作为双向复合地基的横向增强体,建立双向复合地基室内模型,定时监测复合地基及其各组成部分(包括褥垫层、桩体加固区和桩底持力层)的沉降、土工格栅应变和土工格栅上下的土压力;分析经不同时长老化的土工格栅对双向复合地基及其各组成部分沉降、土工格栅应变和土工格栅上下桩土应力比的影响规律。试验发现:双向复合地基及其各组成部分沉降值和土工格栅应变量均随土工格栅老化时长增大而增大;土工格栅下侧桩土应力比和复合地基承载能力均随土工格栅老化时长增大而减小;土工格栅上侧桩土应力比与土工格栅老化时长无关。

In order to study the influence of geogrid aging on bidirectional reinforced composite foundation, an indoor scale simulation was carried out. Geogrid was aged by a method of thermal oxidation and photooxidation first. Geogrid with different aging time was selected as the lateral reinforcement material of the bidirectional reinforced composite foundation. Settlement of composite foundation and its components (including cushion layer, pile reinforcement zone and bearing layer), geogrid strain and soil pressure around geogrid were monitored. Regular patterns of geogrid strain, stress and settlement in composite foundation were discussed. Conclusions are as follows: Settlement of composite foundation and its components, geogrid strain increased with geogrid aging time;pile-soil stress ratio under the geogrid and bearing capacity of composite foundation decreased with geogrid aging time;pile-soil stress ratio upper the geogrid was irrelevant to geogrid aging time.