Geomechanics and Geotechnical Engineering
LI SHUCAI
New development on ahead prospecting water and mud inrush in tunneling
Abstract: Ahead prospecting water and mud inrush is an essential part in tunnel construction, which plays an important role in tunnel information construction，disaster prevention and safety guarantee. To solve the prospecting problem with complex environment in tunnel, ahead 3D IP, tunnel seismic prospecting and multi-point array TEM are introduced into tunnel for prospecting adverse geology. For drilling and blasting tunnel, moving same-polarity sources array method (MSSAM) is put forward, and it has the advantages of forward focusing and backward shielding. Though discussing relationship between water volume and IP decaying information, estimating water volume of water-bearing structure method is proposed. For TBM tunnel, MSSAM provide a useful approach for ahead prospecting in TBM tunnel. TBM equipped 3D IP prospecting method is applied for prospecting geology in field engineering. The seismic method and bore-hole GPR are suggested to be chosen for TBM. In order to suppress the multi-plicity of inversion result, jointed tunnel seismic prospecting, multi-point array TEM with ahead 3D IP, the four-stage integrated prospecting system for tunnel is established. The joint inversion with prior struc-tural information constraint is introduced reduce multiplicity further. Field tests show that multiplicity is reduced and detection accuracy is improved by integrated prospecting, it provide a feasible way for pro-specting water and mud inrush in tunnel.
Key words: water and mud inrush, ahead prospecting, ahead 3D IP, four-stage integrated prospecting, field test.
