Study On Uneven Reinforcement Of Deep Foundation Pit Retaining Pile In Wulong Space Hotel

Due to the short history of the development of deep foundation pit engineering in China,the backward theoretical research and the limited technical level of engineering personnel,some deep foundation pit engineering accidents have occurred in China in recent years.Therefore,it is necessary to fundamentally strengthen the theoretical research of deep foundation pit engineering,This paper is based on the Xi ’an Wulong Space Hotel project.The influence of reinforcement method of bored cast-in-place pile on supporting effect in pile anchor support of deep foundation pit is studied and analyzed.In this paper,the original support scheme was numerically analyzed using MIDAS GTS,and the numerical analysis results were compared with the actual monitoring values to verify the rationality of the numerical analysis.Then,using the material parameter data of soil layer and its supporting structure in the model,through the comparison of the numerical analysis results of piles with different reinforcement methods,the influence law of reinforcement methods on the supporting effect of bored cast-in-place piles is obtained,and the optimal reinforcement form is found.The main results of the research and analysis are as follows:1.Under the same reinforcement ratio,among the six reinforcement forms in the first group,uniform reinforcement and 10(13,7)(segment)– 13C22 mm on the empty side above the bottom of the foundation pit,7C22 mm on the empty side below the bottom of the foundation pit,and13C22 mm on the middle side of the soil,the two reinforcement forms have similar supporting effect and are better than the other four kinds of reinforcement on one side.The other side of the reinforcement reinforcement to reduce the way.2.When the reinforcement of the retaining pile meets the flexure bearing capacity,the deformation and settlement of the foundation pit will be reduced if the reinforcement continues to be added on the empty side or the middle side of the soil,but there is no obvious influence on the overall supporting effect.3.The reinforcement distribution of the pile section according to 90° and the direct distribution of 180° have no obvious influence on the supporting effect.4.Taking the bottom of the foundation pit as the boundary,the empty side above the bottom of the foundation pit is 13C22 mm,the middle side of the soil is 7C22 mm,the empty side below the bottom of the foundation pit is 7C22 mm,and the middle side of the soil is 13C22 mm.This kind of sublevel reinforced cast-in-place pile has better supporting effect when the reinforcement has a certain lap length.However,compared with the lap length of 0.5m and 1m,there is no obvious difference in support effect.Moreover,when the lap length of 1m is overlapped,the amount of reinforcement is increased and the cost is increased.5.To sum up,among several reinforcement forms considered in this paper,11(lap 0.5m)--13C22 mm on the empty side above the bottom of the foundation pit,7C22 mm on the middle side of the soil,7C22 mm on the empty side below the bottom of the foundation pit,13C22 mm on the middle side of the soil,and0.5m on the lap length,this reinforcement form has the minimum deformation and the best supporting effect.