Impact Analysis Of Different Excavation Methods On The Soil Tunnel Under Rich Water Conditions

Hefei Metro Line 1 in the building, through the Nanfeihe Shiwuli, Chaohu near future Line 4 Line 5 will cross the Swan Lake, groundwater resources are relatively abundant in these regions, which was built in the 1st line Nanfeihe position beneath the river width 50 m, head depth 4-12 m, which will not only increase the pore water pressure, but also adversely affect the shield tunnel excavation. Hefei Metro commonly used method of shield tunnel excavation, and in water-rich conditions, have to consider the fluid-solid coupling seepage field and stress field, and therefore whether or tunneling shield method adopted is the best choice to find out with other excavation for the tunnel stability affect soil differences, and thus provide a reference for future rich water under conditions of urban subway tunneling mode selection, will have important theoretical and practical significance.Study of three different ways to tunnel excavation soil stabilization paper Hefei Fengyang Lu, Metro Line 1 South Station- Central Station through a tunnel excavation Nanfeihe engineering background literature research, theoretical analysis and numerical simulation methods influence, the main research work as follows:(1) First, summarized the research background and significance, research status at home and abroad to introduce rich water conditions the tunnel excavation, tunneling and explore theoretical methods of soil stability under the condition of water-rich.(2) Analyzes of groundwater on the mechanism of soil, convection coupled solid basic equations summarize, respectively, the three excavation mechanism research.(3) With Hefei Metro as engineering background, method of numerical simulation,4. After then, I will use the method of elastic response history analysis and the inelastic response history analysis by the module EPDA in the software PKPM. The data include layer displacement and displacement between layers, layer shear force, bending moment, and so on. I will make lists and graphs by these data and the compare the different between them. Moore uses Coulomb constitutive relationship established excavation model under 5m, 10 m, 20 m head conditions shield, comparing the excavation and support of water inflow, stress field, displacement field changes the distribution of plastic zone size, so as to arrive shield changes in the value configuration method excavation.(4) In the same section of a single side heading method, three steps Reservation Core Soil excavation two kinds of methods of numerical simulation of excavation, the excavation also compare Inflow support after the change of the stress field, displacement stress, plastic zone size, respectively, lead to concrete changes in the value of water under the conditions of a single rich side heading method and three-step reservation core Soil tunneling time.(5) A comprehensive comparative analysis of water-rich conditions in three different ways in the tunnel excavation water inflow, stress field, displacement field, the distribution of plastic zone, combined with the status quo in Hefei Metro comparison against a preferred embodiment.