Analysis of the Influence of the Diameter of Isolated Pile in Deep and Large Foundation Pit on Adjacent Existing Underground Structures
Setting up isolation piles is a common protective measure for adjacent underground structures during foundation pit ex-cavation,which can reduce the adverse effects caused by foundation pit excavation.Mastering the influence law of the changes in the diameter of isolation piles on adjacent underground structures is an important prerequisite for reasonably setting the diameter of isolation piles,and for ensuring the smooth construction of foundation pits.This paper takes the civil deep foundation pit pro-ject close to the 1F4 underground station of Riyadh Metro Line 3 and the north side of the interval tunnel in Saudi Arabia as an example,the isolated piles with diameter of 400 mm,600 mm,800 mm are taken as the research object.The three-dimensional model was established by using the finite element analysis software madis GTS to study the impact of enclosure pile construction,excavation to the base,and back building to the roof on the adjacent underground structure.The deformation value shows that the excavation of foundation pit has the greatest impact on the horizontal deformation of the underground tunnel,and too small isolated pile diameter may cause it to exceed the allowable deformation value.When determining the size of isolation pile,the allowable horizon-tal deformation of the underground tunnel should be given priority,and then the pile diameter at the turning point where the verti-cal deformation of the underground tunnel decreases significantly should be selected as the optimal pile diameter.This study can provide some reference for similar engineering construction.
foundation pit excavationunderground structuremadisisolated pile
万方数据
维普
