Research On Supporting Scheme Of Foundation Pit Engineering In Qingdao Qiyang International Hotel

With the rapid development of society and economy,human infrastructure construction,including municipal,subway,water conservancy,underground engineering,construction and other fields,needs to carry out a great deal of foundation pit support work,in the city with high cost of land,how to efficiently obtain the underground space technology is favored.Although the foundation pit engineering is the temporary structure,but its cost is higher(up to tens of millions),the costs for foundation treatment of soft stratum in Shanghai,Shenzhen and others cities account for more than 50% of the overall cost of the project.The supporting structure is a key link in foundation pit engineering,many engineering accidents have also occurred due to the unreasonable supporting structure program.In order to optimize the supporting structure of the foundation pit,improve the quality of the project and reduce the cost of the project,on the basis of systematically understanding of the basic principle of foundation pit support,it is imperative to study and optimize the design of supporting structure of foundation pit.This paper has made deep analysis of the engineering geological conditions of the foundation of Qingdao Kaiyang International Hotel through the engineering geological survey report,site investigation,access to literature and so on of Qingdao Kaiyang International Hotel.On this basis,according to the engineering requirements,the supporting scheme for foundation pit is determined according to relevant regulations.Data investigation and design analysis are adopted.Through the analysis of the geological condition of Qingdao Kaiyang International Hotel,three kinds of support schemes such as pile anchor,steel sheet pile and soil-nailing wall are drawn up for preliminary design,and detailed parameter optimization design is respectively calculated,the feasibility,safety,reliability and economic rationality of each scheme are technically demonstrated,so as to make the scheme reach the final optimization.Numerical simulation method is adopted.Lizheng deep foundation pit software is used to carry out checking calculation of such three kinds of foundation pit supporting scheme design and the solution of deformation,the finite element software PLAXIS is combined to simulate and analyze such deep foundation pit,based on the strength reduction method embedded in the software,the yield criterion and failure criterion are selected,the stress-strain in the process of foundation pit support is calculated and analyzed to get the internal force of the supporting structure,the deformation result and the location ofthe most probable slip surface of the foundation pit in the construction process under the support of the soil-nailing wall,taking the safety and economy into account,the soil-nailing wall is verified to be the best scheme of the project.Engineering inspection and verification method is adopted.Combined with the current codes and regulations,horizontal and vertical displacement of the slope and supporting structure of foundation pit have been monitored,as well as the monitoring program of building deformation around the foundation pit has been designed.A total of 15 observation points are arranged on the top of the soil-nailing wall slope.The monitoring data show that the cumulative maximum displacement of the soil-nailing wall supporting section is 17.9mm,which meets safety requirements.