【摘要】 华南沿海发育各种类型的红壤型风化壳,其中以花岗岩风化壳的厚度最大,风化层最完整。在雨季,地下水沿不透水风化层面流动的结果,常导致崩塌、滑坡、滚石及局部陷落等地质灾害的发生。人类的生产活动或地震等诱发因素,加剧了这类地质灾害。本文通过典型地区的研究,结合大区域的地质情况,提出预测意见和防治对策。更多还原

【Abstract】 Devolution and landslip of weathering crusts are the common and frequently-occurring geological disaster in South China coast, though its scale is always smaller than large landslides which occur in southwest and northwest China, they can exert an unfavourable influence on the urban development, water conservancy facilities ,main line of communication and numerous large engineerings or lifeline projects due to their frequency.Granite is the bedrock widespread in the South China coast. Its weathering crust not only has large thickness but has a relatively complete profile and thick red soil strata caused by:(l)Influence of rock component :on one hand ,the difference of expansion coefficient for various minerals caused the rock surface to be cataclastic during the process of ther- mal expansion-cooling shrinking,and then caused the consolidating force to be lost between rock particles, which is favourable for bedded weathering and strata disintegration ; on the other hand, the hydrolysis of quartz, silicate minerals and alumino-silicate minerals can easily form weathering crust under the climatic conditions of tropics and south subtropics. Granite therefore acted as the geological basis of landslip disaster in South China coast.(2)Influence of lithological characters-development joints are favourable for the activity of surface water and subterranean water,they can go deep into the interior of granite and form thick weathering crust.The main character of weathering-crust slip is its downslope movement, namely the slide body and slide surface are parallel to the slope. Underground water flows along the non-infiltration surface, which causes the surface to become a sliding surface and the overlying weathering crust (strata )a sliding body. This downslope bedding structure is a structural type which can most easily slide.Field observation and calculation show that,water is of vital importance in determining whether devolution or landslip of a weathered crust is able to occur or not. But in the case of full infiltration, the influence of seismic force can increase the probability of weathering-crust landslip by 25%. Human being’ s disorderly production can damage natural slope angles and frequently cause these geological disasters.The prevention and cure of weathering-crust landslip use common experiences, methods of prophylaxis and treatments for landslide, in addition, the following works must be prepared according to its features;(1) Investigation of geological basis, namely researching the mechanism of origin and development of granite weathering crust and studying the influence factors.(2) Investigation of seismicity, mainly the seismic intensity zonation of various scales.(3)Applying the theory of slope development to directing the prevention and cure of weathering-crust landslip.(4)Devoting much attention to the probable calamity caused by the weatheringcrust landslip when planning urban development or construction of large engineerings, traffic pivot,lifeline projects,large reservoirs and river dikes. The prophylaxis and treatments of these geological disasters must be placed on the systematic engineering of environmental protection in order to provide against possible trouble.更多还原