济宁市城区地面沉降的成因和规律性探讨

在阐述济宁市城区自然地理、地质概况、水文地质条件、岩土体物理力学特征的基础上,利用地下水开采情况、地下水位动态、沉降观测及各种地层的有关参数等资料,分析了地面沉降产生的原因、发展现状和发展阶段,并通过对地面沉降和地下水开采的相关分析,认为目前地面沉降正处于较明显沉降的发展阶段,其产生的原因主要在于对深层承压水的超采,与地壳新构造运动无关.地面沉降的分布和发展具有如下规律:(1)地面沉降的速率和分布范围与地下水位的下降一致;(2)地面沉降与地下水位变幅呈正相关;(3)地面沉降速率受岩土体类型的影响,沉降漏斗与粘性土地层厚度的分布基本是一致的;(4)地面沉降中粘性土层的塑性变形和砂性土层的弹性压密并存.图2,表1,参8.

The genesis and regularity of land subsidence in Jining urban area

Referring the foreign and domestic researches of land subsidence,analyzing the physical geography,the geology survey,hydrogeology conditions,the soil characteristics of physical mechanics,this paper arranged the groundwater exploitation circs,groundwater height dynamic state,the data of settlement observation and stratum parameters,and analyzed the causation,state-of-the-art,evolution stage of land subsidence in Jining.From the correlation analysis of exploiting groundwater and land subsidence,the paper summarize land subsidence is being in the phase of obvious subsidence.The main cause of land subsidence is over-exploiting deep artesian water and we can eliminate ultimately the probability that geotectonic movement of lithosphere bring land subsidence.The orderliness of land subsidence is as follows:(1) The rate and the distributing range of land subsidence accord with declines of groundwater level;2 The relation of land subsidence and amplitude of ground water level is positive correlation;(3) The speed rate of Land subsidence is influenced by soil type,so the distribution of subsidence funnel accounts with that of the clay soil thickness;(4) The plastic deformation of clay soil and the elastic deformation is concurrence in land subsidence.2figs.,1tab.,8refs.