中国“采水型”地裂缝特征和成因分析

过量开采地下水诱发的地裂缝("采水型"地裂缝)灾害对社会造成严重损失,受到人们普遍关注。近几十年来,国内外学者对其成因机制进行了大量研究,取得了丰硕成果。本文系统分析了前人的研究成果,归纳出"采水型"地裂缝的差异沉降成因、拉张性水平应变成因和四种成因模式;然后针对中国三个典型的"采水型"地裂缝发育区,即汾渭盆地、华北平原、苏锡常地区,阐述了各地地裂缝分布、发育特征和成因机理,并选择典型地段地裂缝进行成因分析,认为汾渭盆地和华北平原地区部分地裂缝属于"先期断层模式",而苏锡常地区地裂缝总体属于"基岩起伏模式",并阐述了该模式下导致地裂缝发育的差异性变形、水平应变作用机理。

Features and Mechanisms of Earth Fissures Induced Groundwater Withdrawal in China

Excessive exploitation of groundwater in China has induced serious earth fissure hazards, which can cause significantdamage and heavy economic losses, and has received significant attention. In recent decades, mechanisms of earth fissures induced by groundwater withdrawal have been studied by researchers worldwide and many remarkable achievements have been accomplished. The results of previous studies were analyzed in this article firstly and then the mechanisms of earth fissure induced by excessive exploitation of groundwater were summarized and categorized as differential subsidence, horizontal tensile strain, and Four Earth Fissure Formation Conceptual Models. Then the distribution of earth fissures, development features and mechanisms of earth fissures in three regions (i.e., the Fenwei Basin, North China Plain and Su-Xi-Chang in China) where typical“groundwater-withdraw-induced” fissures developed, were elaborated, and a typical earth fissure was chosen to analyze its cause. Results indicate that earth fissures in the Fenwei Basin and North China Plain were mainly caused by pre-existing faults and excessively ground water exploitation, while the fissures in the Su-Xi-Chang region were generally induced by a“bedrock ridge”below the aquifer and excessively ground water exploitation.Differentialcompactionandhorizontalstrainmechanismscausingthedevelopmentofsuchearthfissureswerethenexplained.