Application Research Of Pile Anchor Support In Foundation Pi Excavation

Lhasa City Youth Palace Foundation Pit is located in Lhasa City Stadium,No.18 Jiangsu Road,Chengguan District,Lhasa City.It is adjacent to Polinka Road in the south,bordering Lhasa River to the south of Polinka Road,Jiangsu Road in the north,Linjiao East Road in the east and Ecology Park Road in the west.The basic shape of the foundation pit is roughly inverted L shape,the perimeter of the foundation pit is 600 m,the total construction area is 26843.45m2,and the floor area of the building is 7122.10m2.The youth is planning to build a basement and a five-story building on the ground.The depth of the foundation pit varies from 5.6m to 6.4m.In combination with engineering geological conditions and the use requirements of foundation pits,it is proposed to adopt the construction method of grading excavation and netting support.Since there are loads of adjacent buildings in the upper part of the foundation pit,the method of supporting pile support in this area is adopted.Construction is carried out.The paper has worked on the following aspects and obtained the following research results:(1)On the basis of on-site investigation,the actual construction of the foundation pit was mastered,and it was learned that during the excavation of the foundation pit,the section excavation and support of the foundation pit is based on ensuring safety first.Preventing excessive deformation of the foundation pit has a good effect.(2)According to the geological survey results displayed by the geological survey data,the main distribution of the strata in the area is known,and the traditional stratum treatment method is considered,combined with the special natural environmental conditions such as Lhasa alpine and hypoxia,resulting in the strength and experiment of the support structure.There is a certain gap between the room and the quasi-strength strength values.It is analyzed that the strength of the reinforced concrete after curing needs to be reduced and calculated when calculating the strength of the supporting structure.(3)According to the geological survey report,the physical and mechanical properties of each layer are learned,and the earth pressure received by the foundation during the excavation process is calculated according to the physical and mechanical properties of each layer.(4)Calculate the maximum displacement amount theoretically generated after the foundation pit support,and find the actual displacement of the foundation pit under the condition of 1:2 grading net spray support by laying the displacement monitoring point.The numerical simulation of FLAC3 D simulates the maximum displacement of the most unfavorable point of the foundation pit.After the calculated value,the actual value and the simulated value,the result shows that the foundation pit is in astable state under certain conditions.The displacement of the foundation pit is obtained by means of support.Obvious control.