| The high-speed development of communications career at home poses an increasing demand of deep,long mountain tunnels.It's a challenging technical problem to build tunnel in high hydraulic pressure karsts area at home or abroad,particularly under the current stringent environmentally-friendly prerequisite.We should not drain ground water without thinking,but should be updated with'combined with preventing,cutting,draining and plugging and adaptation to local conditions'.Many mountain tunnels been built and building tells us that various kinds of karst geological disaster caused by high hydraulic pressure is everywhere,poses a great threaten to construction and operation of tunnel.The problem to high hydraulic pressure in karst tunnel is inescapable during the phase of design and construction,and has aroused tremendous attention from men of insight worldwide.Systemic research is based on the case project of Qiyueshan Tunnel,take means of theoretical analysis and field monitoring,study on the distribution rule of water pressure upon lining in subject to high hydraulic pressure mountain tunnel.Major research results are as follows:1.Derived the calculation formula of rock mass permeability by means of theoretical analysis,and applied to Qiyueshan Tunnel.Take Qiyueshan Tunnel into four parts,and calculate it's rock mass permeability is between 1.2×10-6and 1.9×10-5m/s.Which is excellent agreement with investigation results before.2.Summarize the rules of rainfall,water inflow and water pressure by means of field monitoring,then summarize the distribution rule of water pressure upon lining in subject to high hydraulic pressure mountain tunnel under the condition of'stop firstly,drain slightly'.3.Based on engineering geological conditions and hydrogeology conditions,deep analysis the cause of low water pressure upon lining of entrance part,and point out that water pressure upon lining of exit part is higher because of the groundwater type turn unconfined water to confined water. |
PDF Full Text Request