雷州半岛胀缩土地裂缝及其成因机理

本文简述了雷州半岛胀缩土地裂缝的特征及分布发育规律；分析了胀缩土地裂缝的成因。认为雷州半岛胀缩土地裂缝的形成发育是胀缩土以及气候、植被、地形地貌、水文地质作用等因素综合作用的结果。其中胀缩土含大量的亲水矿物和失水产生向心收缩的特性从而成为地裂缝成生发展的内因。而特定的气候、植被、地形地貌、水文地质作用等外部环境条件则是导致胀缩土失水和发展形成地裂缝的重要外因。桉树是一种吸水-蒸腾能力极强的树种，树根的干燥作用是导致了林区土体干燥-收缩和形成收缩应力场及在林地边缘产生地下暗裂缝的关键因子，而极端的干旱气候环境和久旱后第一场大暴雨则是暗裂牵动式胀缩土地裂缝发育形成不可或缺的因素。胀缩土地裂缝灾害应重在预防，有关的策略包括防水保湿、科学植树、建筑设计和地基处理、科学选址。

Origins and mechanisms of ground fissures in Leizhou peninsula,south China

The study of characteristics and distribution of swelling soils in Leizhou Peninsula shows the formation of ground fissure is related with climate,landform,hydrogeologic process.Swelling soil contained hydrophile minerals with characteristics of shrinkage from outside to center by lost water is considered as the internal factor;Meanwhile the important external factor of enviornmental condition of certain climate,vegatation ,landform and hydrogeologic process resulted in ground fissure has been discussed.Eucalyptus are a kind of tree with strong capabitity in absorbing and evaporating water.The dryness of them leads to different fissuring mechanism of close-type ground fissures from open-type ground fissures.The dryness of root is regarded as the major factor for the formation of close-type ground fissure by forest soil evaporation-shrindage.The extreme dry climate and the first storm after a long dry period is regarded as the essential factor for development of swelling ground fissure.