The Influence Of The Built-in Depth Of Supporting Pile For The Foundation Pit

With the speeding up of urbanization,a large number of people are coming to super city just like Beijing,Shanghai and so on for work.Meanwhile the large population density brings a lot pressure to the city's public transportation.And subway is undoubtedly one of the ways to ease the pressure in recent years.Some of the subway station are completed by the construction of deep foundation pit excavation.For keeping the building around the subway station safe,there are more and more academic research about the deformation of the deep foundation pit excavation to help subway station construction in safe.In the site of Beijing Subway 16th line Wenyanglu Station,we found that the settlement of ground surface is so large and has exceeded the alarm value.Except for man-made influence,other occasional factors and abnormal data interference,the supporting structure is deformed because the embedded depth of support pile is not enough.So we analyze the monitoring data and numerical simulation data to find out how the embedded depth of support pile influence the deformation.The research content are:1?Find out the deformation characteristics of support pile via the monitoring data.2?Establish a FLAC3D model of the deep foundation pit excavation of Wenyanglu subway station to restore the actual construction,and measure if it's workable by the monitoring data.3?Compare several plans of different built-in depth of the support pile,and find out a reasonable range of the depth.The final conclusions are:1?We found that the middle part of deformation curve is taller than the part on the both of ends,and the horizontal direction maximum deformation of the supporting pile is about 0.3%H("H" the depth of foundation pit excavation),which is mostly focus on the range of 15-17m.2?The horizontal direction maximum deformation of the support pile become smaller when the built-in depth is becoming bigger and become steady when the embedded depth is over 9m.