浙江温州永强平原地面沉降成因初探

The preliminary study of land subsidence in Yongqiang plain Wenzhou city Zhejiang province

本文在阐述永强平原自然地理、第四纪地质、水文地质的基础上,对近年的地下水位和地面沉降监测数据进行分析研究后,从地层结构和地下水动态两方面初步探讨了地面沉降的成因。Ⅰ组孔隙承压水原始静水位接近地表,从九十年代末期开始以较大幅度下降,2006年之后开始回升;地面沉降速率呈现与地下水位相同的变化趋势。平原区上部厚层粘性土是地面沉降的主要压缩层,通过对粘性土物理力学特征的初步分析认为全新统上段、中段最易产生沉降,地面沉降严重程度与地下水水位动态密切相关,地面沉降速率与地下水位呈正相关性,对Ⅰ层孔隙承压水的过量开采是造成永强平原地面沉降的主要外因。

On the basis of Yongqiang plain natural geography,quaternary geology and hydrogeology,this paper researched the underground water level and land subsidence monitoring data in recent years,discussed the cause of land subsidence from two aspects of strata structure and groundwater dynamic. The original static water level of Ⅰ group pore confined water was close to the surface,began to drop considerably from the late ninety and rebounded after 2006,land subsidence rate change trend is the same as the underground water level. The upper thick layer of cohesive soil is the main compression layer of ground subsidence,Holocene strata is easy to be compressed through the preliminary analysis of the cohesive soil physical and mechanical characteristic,ground subsidence extent is closely related to the groundwater level dynamic,has positive correlation with underground water level,excessive mining of Ⅰ pore confined water is the main reason of land subsidence.