Optimal Design Of Supporting System Based On Controlling The Response Of Buildings Adjacent To Excavation

With the continuous development of the economy, more and more deepexcavations come to cities.The environment that surrounds the deep excavation hasbecome increasingly complex. Generally these deep excavations are near to theexisting buildings because of the land shortage in cities. Excavations are very likelyto cause different degrees of damage in those surrounding buildings. Therefore, theimportance of considering the response of buildings to excavation during the designphase is increasing. In this paper, the background project was Huayuan·Central Chinadeep excavation project, based on the response of adjacent buildings duringexcavation the optimal design method of pile anchor retaining structure design wasproposed and applied in engineering practice. This paper has accomplished followingworks:At first, on the basis of a large number of literature research, this paper analyzedthe displacement pattern of pile-anchor retaining structure in deep excavations,summarized the cracking mode of buildings due to uneven settlement, discussed theassessment of building damage and the evaluation criterion of cracks in walls.Second, numerical model which combined supporting structure, soil, buildingwas established by using finite difference method. The impact of excavation wereobtained by changing the floors, pile lengths of pile foundation, distance from theexcavation to the building in the finite difference method. The deformation patterns ofsurrounding buildings due to excavations were obtained. Then some principles ofmonitoring points settings during excavations were proposed.Third, during pile anchor retaining structure design phase the surroundingbuildings could be protected by controlling the defomation and moment of the mostdangerous places in surrounding buildings.The response of the surrounding buildingswas analyzed by changing pile diameter and pile spacing. Some ideas of pile anchorretaining structure optimal design by controlling the response of the surroundingbuildings were proposed.At last, the method was applied to the design work of HuaYuan deep excavationproject in Changsha downtown area, the pile-anchor retaining structure design wasoptimized. The project cost was calculated in order to chose a cheaper plan. Themonitoring data showed the practicability of the method in this paper.