Design And Technical Economic Analysis Of A Subway Station Track Laying Base

With the rapid rise of the global subway market,the construction of subways is also in full swing in various cities,and subway construction has effectively alleviated the problem of urban traffic jams.In the process of subway construction,the problem of setting up the track laying base is often faced.It is necessary to leave a large size hole(30m×5m)in the top and middle slab of the structure for track laying.The opening of the track laying base has a large horizontal dimension,and the side walls and roof slabs are often Independent support measures cannot be taken,and the structure faces the risk of collapse and deformation.Under the action of lateral earth pressure and top load,the force and calculations at the rail wells of the large tunnel are obviously different from those of other unopened parts.The study on the stress of various parts of the large-size openings on the roof and middle slabs of the station structure,the design of the enclosure structure at the openings,and the budgetary analysis of different track laying bases lack comprehensive and detailed research.Therefore,it is necessary to develop large-sized subway station track laying bases.Comprehensive analysis of tunnel support plan,structural plan and budgetary estimate.At present,the four common scheme designs for track laying bases in China include:(1)double-row pile support scheme,(2)pile + anchor cable support scheme,(3)buttress column scheme,(4)rail row wells at the mid-span position of the double column above the double storage line.This thesis first conducts research and analysis on the plan design and theoretical knowledge of track laying bases at home and abroad through data retrieval,theoretical learning methods,survey methods,and expert interview methods.The main research contents are as follows:1.According to the geological conditions and soil parameters of the airport east station,the pile diameter,pile spacing,embedded depth,and the net distance between the front and rear piles of the double-row bored piles are analyzed through numerical simulation calculations,and the most economical and reasonable support Plan,and calculate the project estimate of the plan to provide a basis for subsequent comparison and selection.2.Analyze the support plan of pile + anchor cable,study the free section of the anchor cable,the length of the anchored section,the vertical distance of the anchor cable,the pile anchor type(1 pile 1 anchor vs.2 piles 1 anchor)According to the most economical and reasonable support plan for stress deformation,pile spacing,segmented reinforcement,etc.,and calculate the project estimate of the plan.3.Using Midas Gen finite element analysis software,study the stress of the frame beam,buttress column and buttress column in the buttress column system after the failure of the enclosure structure,and calculate the project estimate according to the force result.4.Using Midas Gen finite element analysis software,study the stress conditions of the roof,side walls,bottom plate,and top middle longitudinal beams after the large-size openings between the longitudinal beams of the dual storage line scheme,and calculate the project estimate according to the force results.After numerical simulation calculation,project investment comparison and comprehensive analysis with reference to the construction experience of similar domestic projects,it is believed that the pile + anchor cable scheme is most suitable for the design of the track laying base of this project.The anchor cable,as part of the supporting structure,can well bear the soil The lateral bending moment caused by the side pressure load and the external ground overload,the anchor cable support is economical,safe and reliable,and can provide valuable experience for the subsequent subway construction projects in Urumqi.