Study On Cement-Silicate Grouting And Testing Technology For The Surrounding Rock Broken And Water Rich Of Tunnel

With the rapid development of social economy and the increasing demand for traffic engineering,the construction scale of highway,tunnel and other foundation projects is getting more and more large.The engineering is extending to the complex geological conditions and difficult construction areas.Grouting technology has been widely applied to a large number of foundation projects in recent years.The rock mass of Bangshan tunnel is broken and the surrounding rock stability is extremely poor.There are karst caves in some locations,and the water rich condition of the rock is obvious.Under this circumstance,this paper carries on the spot investigation and the relevant experience,adopts the new cement-silicate(C-S)double fluid grouting technology.Indoor test,field test,grouting effect test and a series of systematic methods are adopted to deal with the adverse factors that threaten the tunnel safe construction.Therefore,the following research and analysis are achieved:(1)Analysis of water rich and breakability of Bangshan tunnel surrounding rock.Testing rock mass physical and mechanical indexes such as uniaxial compressive strength and softening coefficient.And the sandstones submerging test for 20 days,and the rule of total dissolved solids(TDS)variation rule with time was obtained.(2)Laboratory study on the controllability of cement cement-silicate(C-S)slurry gel.By changing the ratio of silicate concentration,W:C and C:S,analyzing a large number of cross tests and comparison,the grouting ratio and other optimum parameters of different surrounding rock broken and water rich are given.(3)Field test study on grouting in water rich fractured surrounding rock of Bangshan tunnel.According to the research results of the laboratory test,the ratio of W:C=1.2:1,C:S=1:0.6,28°Be? is used for field grouting in the K145+348 surrounding rock broken seriously and water rich.Verifying the suitability of laboratory test results.(4)Study on testing and evaluation of grouting effect of surrounding rock.Using geological radar and water injection test to compare the grouting effect.The validity of the grouting has been proved.