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Abstract With a view to water inflow of the fractured fault zone occurred in the Qingdao Jiaozhou bay subsea tunnel construction and via theoretical analysis，laboratory and field test as well as practical application，the experimental investigation on general cement paste，ultrafine cement paste，specially made sulphoaluminate cement paste and cement-sodium silicate double liquid are all conducted；and the necessity of advance pre-grouting with the material of ultrafine cement is obtained. Moreover，the key parameters of grouting have been ascertained and confirmed in practice，i.e. the grout diffusion radius is 1.5–2.0 m，the terminate pressure in grouting is 3–4 MPa，the reinforced ply of grouting is 5–6 m. Through the experimental comparison of multistage forward grouting，multistage retrograde grouting and one-off grouting，the optimal grouting method is determined；i.e. adopting the multistage forward way of one-off full hole grouting. In the construction process，a system of coordinating informationized hole-drilling grouting equipments is probed and developed with the three-boom drill jumbo and top-speed pulper for slurrying，high-pressure grouting pump for grouting and grouting recorder automatically logging the grouting parameters. By implementing the strategy of drilling and grouting conducted at each deployed position simultaneously，drilling and grouting operated on a parallel basis，a highly efficient and informationized advance pre-grouting is thus realized. The grouting effectiveness is mainly focused on the hydraulic discharge of drilling holes(according to the design requirements，hydraulic discharge per linear meter should not exceed 0.15 L/min and local discharge shall be no more than 3 L/min)，and assisted in packer test of hole，which are further supplemented by tunnel seismic prediction(TSP) geophysical prospecting comparison，drilling TV analysis，excavation and tunnel face analysis as well as P-Q-T curve analysis. By the practical grouting for 31 stages，the above mentioned materials，parameters and grouting methods are all proved to be feasible and reliable.
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Received: 11 October 2010
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2011, Vol. 30 
