西安地裂缝地面沉降与防治对策

由于自然地质作用和人为活动影响,西安出现了严重的地裂缝和地面沉降灾害。地裂缝的形成分布与区 域地质构造息息相关,其总体北东向成带发育,平行等间距排列,表现出较强的线性展布规律和垂向位移、水平拉 张与水平扭动的三维变形特征。地裂缝有规律的展布活动,制约了人为诱发的地面沉降的发展,地面沉降只能在 被切割的多个条块体中发展。受地层结构、开采井群分布及开采强度等因素影响,在地裂缝两侧产生的差异沉降 又加剧了地裂缝的活动强度,使其危害大大增强,给城市建设和规划造成了巨大的损失和困难。进一步深入研究 城市地质灾害的形成机理,建立监测预警系统,加强城市规划,限制人类活动和采取工程防护措施等是行之有效的 防灾减灾对策。

LAND FRACTURE AND SUBSIDENCE PREVENTION IN XI′AN

Severe land fractures and land subsidence are present due to geo-process and human activities in Xi′an,the largest continental city in northwestern China. Formation and distribution of land fractures have a close relation to the regional tectonics, and the general extension of the land fracture is NE,arranged and paralleted in equal rank,which reflects strong linear distribution regularity and 3-dimension changing characters of vertical displacement.Horizontal spread and horizontal writhe,the regular destruction activities of land fractures restrict the extension of the man-made land fractures,that can only develop in many narrow cut clots,because of the influence of many fractures such as the layer structure,exploring strength,land fractures and land subsidence bring difficulties and economic losses to city planning,study on city geo-hazard mechanism,construction of monitoring system,reinforcement of city program,restriction of human activities, and engineering precaution are effective countermeasures to prevent and alleviate geo-hazard.