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Abstract In-situ experiments of support system were carried out to investigate bolt axial force，surrounding rock pressure，steel framework stress and tunnel deformation of primary support，contact pressure and steel stress for lining. The results show that under condition of high water content gypsum breccia，the stress of primary support increases by 50 %，and the stress of lining increases by 30 % with respect to drying one. Particularly combined with drying gypsum breccia，bolts at hance were subjected to compression. Accordingly，it suggests that systematic bolts at arch should be cancelled；and only feet-lock bolt should be installed. This could reduce sealing time of primary support significantly. Nevertheless，in terms of high water content gypsum breccia，most of bolts at hance were subjected to tension. Therefore，bolt parameters should be unchanged. Framework of primary support can bear load and is of paramount to support system once it is installed. The results are not only applicable to deep tunnel in gypsum breccia stratum，but also can be as reference for similar engineering.
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Received: 06 January 2012
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2012, Vol. 31 
