The Suitability Evaluation Of Urban Construction In Red-strata Mountain City-

With the acceleration of urbanization process in China,the urban construction land demand increasingly tense.Finding out the suitability and the geological problems,It will be good for the sustainable development of cities.WanZhou,the second largest city in ChongQing,is the the main immigrant city in the Three Gorges reservoir area.With the development of the city,the population and the demand for land is increasing,the geological problems which induced by the construction are becoming more serious.The geological suitability evaluation have a great significance for the sustainable development and reasonable planning of WanZhou.In this paper,The geological suitability were evaluated in Wanzhou,The problem of red-strata slope was studied in WanZhou which is particularity and universality in this area.obtained the following conclusions:1.The red-strata slopes in Wanzhou are divided into three categories according to the difference of lithologic combination of slopes.The instability modes and failure processes of three types of slopes are studied separately.It is concluded that:?The overlying thick sandstone underlying sand and mudstone interbed slope is less likely to form a landslide.The geological problem that needs attention is the collapse of sandstone fragments caused by sexual weathering;?With the slope angle of sand-shale interbed slope and the trend of rock stratum increasing,the safety of slope increases gradually,and the safety factor increases most rapid when the angle between 50°and 80°,it has less influence on the anti-sloping slope than the forward slope.?The sandstone slope is the main distribution area of the collapse.The numerical simulation and field verification are used to propose the safe distance of the Wanzhou,The safety distance of the collapse is 220m.2.Comprehensive analysis for 5 geological factors which include 14 units,the analytic hierarchy process is used to evaluate the geological suitability of Wanzhou,which is divided into appropriate,suitable,poorly suitable and unsuitable.The evaluation subdivisions accounted for 21.478%,40.143%,33.554%,4.825%.respectively.The comparative analysis found that geological disasters are the most influential factors,different utilization suggestions are proposed for four grades.3.Through the comparison of the suitability evaluation results and the actual comparative analysis,it is found that the geological disaster is the most influential factor affecting the construction geological suitability of the urban area of Wanzhou.The suitable distribution area of the suitable area and the suitable area is the main development area of Wanzhou City,and it is targeted to four grades.Suggested corresponding development and utilization methods.