承压层抽水试验中地面沉降曲线斜率的确定

Determination of Slope of Land Subsidence Curve in Pumping Test of Confined Aquifer

地下水开采导致的区域性地面沉降已成为全球性的地质灾害之一。对沉降区控制点的监测和预测是地面沉降研究的主要内容。在以往抽水导致地面沉降的研究中,通常关注单个点的沉降值,通过单点沉降值研究面状区域的沉降特征。本文基于抽水导致地面沉降的沉降距离(δ-ln r)半对数线性关系规律和有效应力原理,通过3种理论推导得到承压层抽水试验中地面沉降半对数曲线斜率的表达式,为确定地面沉降的半对数曲线斜率提供了一个方法,将沉降预测从点延伸向线。通过天津、上海、台湾、美国国内外5个抽水试验监测数据的拟合验证,表达式预测的沉降半对数曲线斜率与实测值相近。该方法可用于承压层抽水试验地面沉降预测。

Regional land subsidence caused by groundwater exploitation has become one of the global geological disasters.The monitoring and prediction of control points in subsidence area is the main content of land subsidence research.In the past studies on land subsidence caused by pumping,it is usually concerned with the settlement value of a single point,and the settlement characteristics of the planar area are studied by every single point settlement value.Based on the semi-logarithmic linear relationship of subsidence-distance(δ-ln r)and the principle of effective stress,the expression of semi-logarithmic curve slope of land subsidence in pumping test of the confined layer is obtained by 3 theoretical analysis,it provides a method for determining the slope of semi-logarithmic curve of land subsidence.The method extends the settlement prediction from point to line.The slope of the semi-logarithmic curve predicted by the expression is close to the measured value by fitting 5 monitoring data of pumping test in Tianjin,Shanghai,Taiwan and USA.This method can be used to predict the land subsidence of pumping tests in confined layers.