圆形构筑物周边土工膜沉降时的褶皱产生机理及分析模型

基于传统薄膜理论建立了下卧土体沉降作用下圆形构筑物周边土工膜受力变形的分析模型,发现在下卧土体沉降作用下圆形构筑物周边土工膜中将产生褶皱,并揭示了其产生机理。进一步通过引入"可变泊松比"概念并基于褶皱薄膜理论建立了褶皱区与张拉区土工膜受力变形的分析模型,分析了下卧土体沉降大小、上覆土压力、土工膜界面强度、圆形构筑物半径及土工膜抗拉刚度对土工膜褶皱程度与受力变形大小的影响。结果表明下卧土体沉降越大、圆形构筑物半径越小,则褶皱程度及土工膜最大应变越大。最后提出了工程上控制土工膜褶皱和最大应变与张力的几点工程措施。

Mechanism and analytic model of wrinkled geomembranes around circular structures subjected to differential settlement

A simplified model to analyze the tension and strain of the geomembranes around circular structures subjected to differential settlement was presented based on the conventional membrane theory.It was found that wrinkles would be induced in the geomembranes around the circular structures and the mechanism was investigated.Further,the analytic model was given by introducing the concept of "variable Possion’s ratio" and based on the wrinkled membrane theory so that the tension and strain of the geomembranes considering induced wrinkles could be analyzed.The effects of the differential settlement,the overburden pressure,the interface strength of the geomembranes,the radius of circular structures and the tensile stiffness of the geomembranes on the wrinkles,the tensions and stains of the geomembranes were also studied.It was shown that the behaved degree of wrinkles and the maximum strain of the geomebranes increased with the increase of differential settlement and the decrease of radius of the circular structures.In addition,some practical measures were suggested for controlling the behaved degree of wrinkles as well as the maximum tension and strain of the geomembranes.