The High Slope Stability Study Of South Foundation Pit Of Lanjiangshandi Garden In Shenzhen

Slope is an important part of the engineering construction. Humans engaged in production and construction process always inevitably modify the surface of lithosphere, which often forms numerous artificially slopes. With the rapid development of our country's economic construction, we often encounter a lot of engineering slope in resources' development and infrastructures' construction. As the slope becomes higher and higher, the stability problems of the slope becomes increasingly prominent because of the increasing project scale and the limited geological condition. In the engineering construction process, slope instability caused peoples' life and property seriously lossed, which caused schedule delayed. And so the indirect loss is immeasurable. It can be clearly seen that the stability problems of the slope related to security and economic benefits during project construction. So, study for its stability has very important engineering practice significance and economic value. With the implementation of the new city's planning in Shenzhen City, it will take the urban area gradually expanded to the surrounding mountains. So far, the similar slope is still rare. Expected in the future, the similar high slope will be occur in large numbers. This study has representative significance.The proposed Lanjiangshandi garden is located in northwest mountain of Futian district. The mountain west up Tanglang Hill, East to Buji Jigong Hill, it belongs to hilly landscape. Located in the northwest lotus pond which six hundred meters far always Liantang reservoir. Venue is surrounded by hills, gulf-shaped. Red line range covers an area of six million and eight hundred ninety nine point zero four square meters. The lowest elevation is about sixty meters. The highest elevation is about one hundred thirty meters. Proposed buildings have 12 buildings. Outside the range of red line is about three million square meters high slope area. The project is mainly for cutting side slope which formed high slope.The entire site is surrounded by mountains, which is high in north and low in south. Because of the limited terrain conditions, it must cut slope. Secondly, because the type of buildings' structure is wall framework and frame structure whose design requires for underground garage, so it should be down to deep dig. It leads to a large area cutting and forms the high slope. After the southern slope been excavated, its height is fifty point eight meters. And the highest elevation is one hundred and twelve point nine meters. The lowest elevation is sixty two point one meters. Presently, the slope is in excavation state. Especially we found a visible crack in the second stage of the platform when the southern slope is on the excavation and support process. The crack will be a serious threat to construction and excavation of pit. The deformation sign shows that the excavated slope is instability. Its supporting design doesn't meet the stability requirements. So, to study the stability of the slope is particularly important.Based on field investigation and data collection method, the paper take the high slope which in the south of the foundation as research objective and research on the stability of southern side slope. The main contents include:(1)With the method of field survey, the paper comprehensively analyzed the area's natural geography and engineering geological environmental conditions from several aspects as meteorology and hydrology landform, stratigraphic lithology, geological structure, hydro-geological conditions and physic-geologic phenomena.(2)Analyze the structure characteristics of slope rockBased on field investigation and statistical analysis indoor, the paper accounted the development characteristic by means of statistical window method and route accurately measuring method. As well as comprehensively grasp the number of groups, density, extension, openings, filling, ups and downs, rough, seepage and structures form scale features of the structure surface. It analyzes the control effect of important structure surface to the structure of slope rock and divides the types of rock structure.(3) Research the rock mechanics parametersBased on GSI index in Hoek–Brown criterion and strength features of complete rock, it analyzes and calculates the equivalent mechanical parameters of rock needed in Morh-Coulomb standard and also it combining indoor direct shear and uniaxial test data determine comprehensively the physical mechanical parameters of rock, which provides basis for the calculation of stability later.(4) The southern slope stability analysisIn the full analysis on the basis of existing slope material, According to the site condition, we choose representative profiles to calculation in different working conditions by the rigid body limit equilibrium method. Use the software Phase to analysis the Two-dimensional finite element numerical simulation, and comprehensive evaluation of its stability conditions.(5)Prevention measuresComprehensive analysis of slope engineering geological characteristics and stability checking results, Combined with engineering slope actual situation, Identify key management area. The paper will puts forward reasonable prevention measures.