Monitoring And Prediction Analysis Of Overpass' Foundation Ditch Which Is Used For Frame-jacking Construction

Along with the development of high-rise buildings and underground structures, excavation depth developed. Meanwhile, along with the development of urban modernization , the utilizations of underground space become more and more generally. Urban underground space development and utilization of the city has now become a major issue, these will bring about large-scale excavation and foundation engineering support. The other hand, as our country's economic and social development, it needs to develop urban transport network urgently, to tie up these cities to be a whole. In actual engineering, there are many projects across the city by road or rail system, when the lines and the urban arterial roads are at grade intersection, it brings lot of interference to the intersection, So for these projects , there are problems for safety and stability of the pit, the other hand, it faces that when the road cross under the existed railway or road ,how does it have any impact to the safety of transportation? With the development of the economic, these projects increases, and the problems are also increasing at all, so the research of security and stability of construction and excavation in this paper would have important theoretical and practical significance.Based on the author's own participation in the jacking framework project that Humin road in South shanghai railway station crossed under Huhang railway, according to the measured data of the excavation pit in the excavation process of the jacking framework, the deformation of the enclosure, the underground water level changes, settlement features of underground pipelines around are analyzed systematically, and according to the measured data in the jacking process of the jacking framework, displacement of the supporting structures on both sides, settlement features of the road tracks and subgrade of the above railway are analyzed. All the conclusions can provide references to the project that are similar to the work referred in this paper for design and construction ,and for both safety and stability of the enclosure , it has some references to establish effective monitoring methods in excavation and jacking framework.In addition, based on variety of theoretical and empirical formula which is measured in the past, according to the specific circumstances of the project, Poisson curve is used for the deformation analysis of the forecast. Practice shows that Poisson curve is very accurate and effective.