外文翻译--中国的地裂缝灾害(编辑修改稿)

外文翻译--中国的地裂缝灾害(编辑修改稿)内容摘要：

res problems. Ten ground fissures distribute over the whole down town area of Xi39。 an city (Figure4) with an aggregate length of 72km, covering 155km2,creeping with an average rate of 12mm/a(vertical shear movement), and ma ximum 70mm/a nearby a new subsidence center (sink rate is over 200mm/a).These ten ground fissures have nearly the same predominant direction (about N700E,parallel to LintongChang39。 an fault),creep in the same way, mainly dip to south with 75℃ ～ 85℃ high angle, separating nearly 1km each other, showing the same tectonic characteristics clearly(GENG, etal,1992).They have bee ten destructive belts, destroyed all kinds of civil engineering located in the belts, made losses of millions US dollars in 1980s. It has been noticed that the volume of over extracted ground water, ground subsidence and ground fissure activity have close correlativity. The rate of decrease of ground water level increase to 4m/a in subside center areas. Ground fissure hazard management 1 Ground fissures hazard prediction According to the characteristics, geological environment and mechanism of ground fissures the potential ground fissures can be predicted. The prediction is posed of three parts: (1) Geotechnical investigation. The present distribution of ground fissures, preexisting faults, potential faults and subsurface shape in concerned area should be investigated. Firstly, according to characteristics and geological environment of ground fissures, aerial photographic interpretation may help to find the locations where there is the maximum of surface elevation gradient to guide the field investigation. Secondly, the field investigation in the potential ground fissures hazard area will help to find some precursors of the evaluation of fissures. Usually, the bending stress bees strong enough to make fine crack on the rigid engineering structures with special pattern before the hazard. Thirdly, geophysical and geotechnical investigation on subsurface conditions of the potential hazard area, including seismic survey, gravity survey, electric survey, radiation survey and soil gases survey, will 4 help to find preexisting faults or other kinds of unsmooth subsurface. Borerhole data will be very useful in the investigations. Figure 1 (2) Monitoring the ground sur。