【摘要】 长期抽取地下水造成了上海严重的地面沉降。本文根据上海砂土层的水位、变形观测资料,研究了上海含水砂层变形特征及其与地下水位变化的关系。研究结果表明:在地下水位的总体上升期、稳定期,砂土层的变形为弹性;在地下水位总体下降期,当水位高于土层历史上的最低水位时,砂土层的变形主要为弹塑性,可用双线性弹塑性模型描述;当水位低于土层历史上的最低水位时,砂土层的变形为黏弹塑性,此时砂土层黏弹塑性的模型为一弹簧体与宾哈姆体并联后再与另一弹簧体串联而得到的模型。根据实测的土层变形和水位数据,可以得到砂土层的变形参数,从而为地面沉降的计算提供依据。更多还原

【Abstract】 Severe land subsidence took place in Shanghai due to long-term pumping of groundwater.Based on the observation data of soil strata deformation and groundwater table the relationship between the deformation characteristics of sand strata and the variation of groundwater tables is studied.It is found that in the periods of groundwater table ascending or keeping steady the sand strata exhibit elastic behavior.Whereas,in the period of descending the sand strata exhibits elasto-plastic behavior when the groundwater table is higher than the lowest in the history.A bilinear elasto-plastic model can be used to describe this behavior.The sand strata exhibit visco-elasto-plastic behavior when the groundwater table is lower than the lowest.A model in which a spring arranged in parallel with the Bingham body and serially connected with another spring can be used to depict the visco-elasto-plastic behaviors of sands.The deformation parameters of sand strata are determined according to the obtained data and provide the basis for the calculation of land subsidence.更多还原