Study On The Design And Selection Of Soil Nailing Wall Support System In Deep Foundation Pit Engineering In Western Shandong Area

With the rapid development of urban construction,a large number of deep foundation pit projects emerge constantly.At the same time,in the face of complex surrounding environment,higher requirements are put forward for deep foundation pit support technology.Luxi area is a typical alluvial plain area of the Yellow River.Due to the perennial silting of the Yellow River,the geological structure is now unique.Soil-nailing wall support system is widely used in foundation pit support in this area because of its fast construction speed and low cost.However,there is not much experience in the design and selection of support system.Therefore,it is of great practical significance to study the design and selection of soil-nailing wall support system in this area.Based on the regulation of special geological conditions,the Yellow River alluvial plain area as the research background,liaocheng shengshi lake deep foundation pit engineering,soil nailing wall supporting system as the research object,using the FLAC3 D three-dimensional numerical model is set up,with the help of numerical simulation combined with field monitoring means of research,research on soil nailing wall supporting system in luxi area,the application of the special engineering geological conditions,selection of soil nail wall supporting system for similar projects provide engineering guidance.The main contents and conclusion of this thesis were as follows:(1)In liaocheng city prosperous time lake deep foundation pit engineering as a case,the deformation and the surrounding environment has carried on the field monitoring,soil nailing wall supporting system,foundation pit at the top of the maximum horizontal displacement is 30.1 mm,foundation pit maximum vertical displacement at the top of the accumulative total of 18.33 mm,deep a maximum horizontal displacement of 30.03 mm,cumulative settlement of surrounding buildings and roads within 10 mm,both in the alarm value range,meet the specification requirements.(2)FLAC3D to establish a numerical model of deep foundation pit engineering,including shengshi lake to,to simulate the foundation pit excavation and soil nail wall support and record the changes of soil displacement and internal force of soil nail,deep foundation pit horizontal displacement at the top of the small,big part of the general trend of soil nailing maximum internal force in the second row,through the simulation results and monitoring results of comparative analysis,the constitutive model of soil is determined and the relevant calculation parameters.(3)Based on shengshi lake three dimensional numerical model for deep foundation pit engineering of soil constitutive and calculation parameters,and the different selection of excavation depth conditions affecting nail wall supporting system research,FLAC3 D respectively established the soil nail wall,soil nail wall,prestressed anchor and soil nailing wall and prestressed anchor + three numerical models,through the study of the comparison and analysis of deformation,choose the right under the conditions of different excavation depth of soil nail wall supporting system,for the design of soil nailing wall supporting system engineering guidance for the selection.