| With the rapid development of China’s economy and the continuous expansion of the cities,urban transport becomes diversified and rapidly developed.Western mountainous cities with complex terrain are also facing with more and more multilateral slope engineering problems in the construction of urban buildings and roads.On the one hand,due to the restrictions on space in mountainous cities,the layout of buildings is complex.On the other hand,the stability of slopes in mountainous cities is directly related to the major decisions in design and construction,and is also related to the selection of project site.So in order to avoid excessive influence on the surrounding existing buildings in the construction process,it is necessary to evaluate the stability of rock slopes in mountainous cities and to optimize the design of the supporting structures of landslides.This paper takes an excavated subgrade rock slope engineering project in Chongqing as the engineering background.This paper makes a systematic study of the spatial effects of slope excavation in mountainous cities,the stability of the slope,the deformation of the slope support structure,and the influence on the adjacent roads and buildings in using of on-site monitoring,theoretical analysis and numerical simulation methods.In this context,taking the project as an example,the design optimization of the anti-sliding piles on the slopes in mountainous cities is studied.The main research contents and conclusions of this paper are as follows:(1)Based on the results of field investigation,combined with complex engineering environment,the stability of the slope in each section of excavation pit is analyzed.And the construction scheme which is combined with the pile anchor retaining wall by the reverse method and the supporting structure is determined,which lays the foundation for the follow-up study.(2)According to the actual situation of the traffic hub station of Sigongli,the field monitoring is carried out by the method of manual and machine monitoring.The changes of the displacement of the main road surface subsidence,the horizontal and vertical displacement of the retaining wall and the anchor cable force of the anti slide pile in the construction process were obtained.The feasibility of the slope excavation construction scheme is verified,and the rationality and safety of the slope supporting structure design are verified.(3)Based on the field investigation and monitoring results,the finite element numerical method is used to simulate the construction process of the excavation and supporting structure of the road-base rock slope in the support project.The law of stress distribution,the slope displacement,the settlement deformation of the upper roadside of the subgrade slope and the change law of the displacement of the anti slide pile are obtained.The result of numerical simulation is similar to the result of field monitoring,and the law was the same.It verifies the rationality of parameter selection and the correctness of calculation results.(4)By using the finite element numerical simulation method,through the study of different excavation schemes for the rock slope in the support project,the change law of the deformation of the upper part of the slope and the slope of the subgrade slope in the different excavation schemes and the distribution law of the plastic zone of the rock and soil under the different excavation schemes are obtained.The study shows that the excavation rate is reduced.And reducing the depth of each excavation can reduce the deformation of the slope and the failure area of the rock mass to a certain extent,and increase the stability of the slope.(5)The numerical simulation method is used to study the horizontal displacement of the anti-slide pile and the slope top of the slope under the conditions of different design factors.The influence law of the design factors and the optimum combination of the design parameters are obtained.And a set of measures to control the deformation of the slope of the subgrade slope is put forward in the mountain city.Optimization design process of application and anti-slide pile. |
