浅埋管幕施工及其受弯引起地表沉降预测方法

Prediction Method of Surface Subsidence Caused by Construction of Shallow Buried Pipe Curtain and Its Bending

针对管幕箱涵暗挖工法在城市下穿工程中引起的地表沉降控制问题,本文依托南昌某地下通道建设工程,基于随机介质理论和弹性薄板模型纳维解,提出了一种预测浅埋管幕支护下箱涵顶进施工中地面沉降的计算方法,并结合现场监测数据和数值模型对该计算方法进行了验证,此计算方法可以使施工人员提前对下穿工程引起的地表沉降值做出预判。结果表明:(1)该方法对地表沉降最终值得预测结果较好,与现场实测数据误差不大于10%;(2)由土体损失引起的地表沉降值较小,最大值为0.52 mm,主要控制纵排管幕上方的地表沉降;(3)由管幕变形引起的地表沉降值较大,最大值为1.70 mm,主要控制通道上方的地表沉降。

Aiming at the problem of surface subsidence control caused by the underground tunnel excavation method of the pipe curtain box culvert in the urban underpass engineering,this paper relies on an underground passage construction project in Nanchang,based on the random medium theory and the Navier solution of the elastic thin plate model,and proposes a prediction method of shallow buried pipe curtain.The calculation method is verified by combining on-site monitoring data and numerical model.This calculation method can enable the construction personnel to predict the surface settlement value caused by the underpassing project in advance.The research results show that:(1)this method has better prediction results for the final value of surface subsidence,and the error with the field measured data is not more than 10%;(2)the value of surface subsidence caused by soil loss is small,the maximum value is 0.52mm,It mainly controls the surface subsidence above the tandem pipe curtain;(3)The surface subsidence caused by the deformation of the pipe curtain is large,the maximum value is 1.70mm,and it mainly controls the surface subsidence above the channel.