垃圾填埋场基础局部沉降对衬垫系统变形影响的试验研究

Experimental study on deformation behavior of geosynthetic liner system subjected to local settlement of foundation

基础局部沉降会引起衬垫系统中的土工膜和无纺布产生较大的拉应变,有可能导致衬垫系统受拉破坏或性能下降。通过模拟试验,采用应变片、土压力盒和位移计,对基础发生局部沉降后土工膜和无纺布组成的衬垫系统的变形进行了研究。试验结果表明:基础发生局部沉降后,沉陷区中心处应变最大,从中心点往两侧应变逐步减小;沉陷区上覆荷载发生了变化;衬垫系统的刚度对变形影响较大。最后,对试验结果进行了讨论,得到了一些有益的结果,基础局部沉降发生后衬垫系统各点应变不同,沉陷区外衬垫系统发生了滑移以及沉陷区内上覆荷载发生了重分布。

The local settlement of foundation will cause tensile strain of geomembrane and non-woven geotextile in the geosynthetic liner system,and greater tensile strain will lead to tensile failure of the geosynthetic liner system or degradation of its performance.The deformation behaviors of the geosynthetic liner system after local settlement of foundation are investigated by use of strain gauges,earth pressure cells and displacement gauges.The experimental results show that the maximum axial tensile strain occurs in the center of subsidence area after the local settlement of foundation,and that the strain gradually decreases from the center to both sides.The overlying pressure on the geosynthetic liner system within subsidence area changes accordingly.Tensile stiffness has greater influence on the deformation.Finally,some useful conclusions are drawn：different locations have different tensile strains;the relative displacement occurs between interfaces;and the overlying pressures on the geosynthetic liner system are redistributed after the local settlement of foundation.