深圳市地质灾害及防治技术

The geologic hazard and its control technology in Shenzhen City

深圳市是一座新兴的海滨城市,市区东部与西部以花岗岩为主,中部以古老的变质岩为主,部分地区分布有砂岩、泥岩及变质的板岩、粉砂岩,深圳大断裂是区内主要的构造形迹。滑坡地质灾害主要分布在中部。在花岗岩地区主要变形为岩质高边坡崩塌、落石、坍塌等坡面变形;在变质岩、砂岩、泥岩地区发生多处滑坡。地质构造与地质灾害关系密切,深圳大断裂两侧为地质灾害多发区。防治边坡变形的工程措施即桩排、连续墙、基础为桩,锚杆框架;预应力锚索、预应力锚索框架护坡、预应力锚索抗滑桩,设置多级平台减载及疏干排水措施。深圳采用的治理地质灾害的工程措施经过多年的使用达到预期效果,但在上世纪90年代初完成的工程很少考虑工程措施与城市的景观协调。90年代后期已经考虑了工程完成后对城市环境的影响。因此采用防护措施以锚杆框架、预应力锚索框架工程为主,框架间植草,既有利于边坡稳定又有利于美化环境。

Shenzhen is a newly coastal city.There are granite in the east and west and old metamorphic rocks in the middle.Regionally,there are sandstone,mudstone,metamorphosed slate,and siltstone.The Shenzhen Rupture is the major tectonic line in the middle area.Thus the geologic hazard of landslide is mainly distriubted there.In the granite area,the deformation primarily are breakdown,rockfall,and collapse of high slopes.For the slopes composed of metamorphic rocks,sandstone and mudstone,landslide only occurs in several places.It also presents the relation between the tectonics and the geologic hazard,which shows that in both sides of the fault landslides developed.In the second part,the engineering technology for slopes are discussed.The technology includes:1.Piles and continuous wall;2.Bolting frame;3.Prestressed anchorage cable,prestressed anchor frame protection slope,and prestressed anchor antislide pile;4.Installing the multilevel relieving platform;5.Unwatering and draining.The construction technology employed in Shenzhen has been proved effective since it was in operation.Otherwise,in the projects accomplished in the early 1990s,the coordination between the engineering measures and the civic landscape was hardly considered.Since the late 1990s the impact on the civic environment of projects has been taken into account.So the protection measures mainly are bolting frame and prestressed anchor frame.Grass is planted between the fames,which is good for the side slope stability as well as for the landscape.