Impact Analysis Of Deep Foundation PitSupporting Structure And Ground Settlement By Dewatering

As the rapid development of our country, national economy and urban construction, a eria land underground space resources are increasingly being developed and deep foundation pit is more widely adopted.In this thesis, analysis and research of the design for foundation pit was carried out in safe, rational and economic principles, considering the foundation pit supporting engineering practice of Henglong Plaza in Shenyang.Carry out numerical design for foundation pit supporting structure. According to the project survey report, calculate and design foundation pit supporting structure strength using the equivalent beam method and analyze the foundation pit stability through numerical calculation. Comparing the obtained results with the design of engineering survey report,there is no big difference between them, so we can consider that a relatively safe design.Based on the good performance of numerical simulation software ABAQUS in practical engineering applications, adopt the software to build two models close to the actual project situation. The first model is to simulate the critical slip surface of the foundation pit, and compared with the proposed design zooming results, the power calculation results is relatively conservative; the second model is to simulate anchor bar stress variation and the results are far less than the zooming stress values. The 3rd and 4th model are to simulate the horizontal displacement offender piles considered or not dewatering. The result is maximum displacements are at the pile bottoms.Summarize and analyze soil deformation mechanism and settlement factors after dewatering, through two dimensional finite element simulation analysis shows:with the decrease of the elastic modulus, ground surface settlement increases, and ground surface settlement curve become steeper, namely the unequal settlement is greater. Maximum ground surface settlement and the elastic modulus distributeas broken lines approximately. When the elastic modulus is small, with the increment in the elastic modulus, maximum ground surface settlement decreases rapidly, but when the elastic is larger than a certain critical value, maximum ground surface settlement change rate reduces; with maximum dewatering depth increases, the total ground surface settlement and unequal settlement increase significantly and maximum ground surface settlement increases approximately linearly; with the increment in permeability coefficient, the settlement curve is closer to a straight line, near foundation pit edges, unequal settlement reduces and in the distance edges, unequal settlement increases. When the permeability coefficient is small, with the increment in permeability coefficient, the maximum ground surface settlement increases rapidly, but when the permeability coefficient is larger than a critical value, the maximum ground surface settlement change rate decreases. And building 2 models based on practical engineering considered or not dewatering, summarize and analyze the ground vertical displacement:while the depth of excavating increases, vertical displacement increases significantly, and the ground has obvious vertical displacement far away from the foundation pit; the distribution form of ground vertical displacement depend on settlement quantity.