Study On Optimization Of Vertical Well Support And Construction Defect Prevention Scheme Of Deep Topsoil Layer

With the rapid development of China’s economic construction,people’s demand for energy is increasing.However,the shallow energy resources have been depleted,and people’s exploitation of energy is gradually transferred to the deep surface layer.The special geological conditions of vertical shaft in deep topsoil make the conventional construction methods difficult to realize,which requires the use of special construction techniques.At present,the freezing method is most commonly used in the construction of vertical shaft with deep topsoil.The freezing method adopts manual or mechanical excavation,which leads to poor construction conditions,high safety risks and large consumption of electric energy.Therefore,this paper adopts the enveloping structure mode of occluded pile with additional lining to construct the shaft in the deep topsoil layer of Wucai Bay.In order to provide reference for the construction and construction of the vertical shaft in The Wucai Bay,Midas GTS software is used in this paper to study the support scheme and defect prevention scheme of deep topsoil layer in Wucaiwan.Through the three-dimensional model analysis of different occlusal piles and lining schemes,the stress and deformation of the vertical shaft occlusal piles and lining are analyzed,and the optimal ratio selection scheme is obtained.At the same time,combining with the engineering geological conditions and hydrological conditions,colorful bay on the defects of the construction process prone to remedy,advance geological forecast method is introduced,the control of underground water level,the pile quality inspection and remedies,to color bay project is of important guiding significance for safe and economic construction,the main work is as follows:(1)With colorful bay topsoil shaft 80 m deep bite pile retaining as the engineering background,3D finite element analysis model is established,the different schemes of envelope structure and shaft wall structure parameters are designed.The numerical simulation analysis and to meet the needs of construction safety and waterproof,finally choose 52(26 reinforced concrete piles,26 root pile)Φ 1000,bite the amount 293.42 occlusive piles,30 cm thick C25 sprayed concrete,steel arch I22b(spacing 5 m)+ 650 mm C40 concrete lining parameters,for the colorful bay engineering construction to provide relevant advice.(2)According to the hydrogeological conditions of the shaft of Wucaiwan Project,the control scheme of underground water level is put forward through calculation: 20 sandless concrete pipes with a diameter of 600 mm are arranged,the depth of the pipe well is 90 m,the spacing of the Wells is 8.2 m,the pumping pump is of 1.8 KW power and the pumping pipe diameter is 40 mm.Of groundwater extraction by the dewatering well,USES the gutter drainage,drainage ditch slope should not be less than 0.3 %,ditch seepage control measures should be taken,considering design plane position and topography and geological conditions,and to reduce the excavation for the principle,from high to low emissions,drainage ditch slope is 1 %,will be drawn to the tube well pumping groundwater influence radius.(3)Combined with the engineering geological conditions and hydrological conditions of Wucaiwan,this paper introduces the remedial plan for the defects that are easy to appear in the construction process,and expounds the specific method of geological advance prediction,the control of groundwater level,the inspection of pile quality and the remedial measures.During the construction of the occlusive pile,the sound wave transmission method was used to nondestructive test the quality of the pile,and the transient electromagnetic instrument was used to detect the quality of the occlusive pile.When quality problems occur in the occlusion,the solutions of high pressure rotary jet grouting pile,in-well grouting and vertical reinforcing pile can be used comprehensively to remedy the problems.