Back Analysis Research Of Rock Parameter For Zone Strengthened By Advanced Small Pipe Grouting On Tunnel

The advanced small pipe grouting is a kind of valid way to reinforce geologic strata in the shallow tunnel construction. However, there is large divergence in handling the strata when establishing the finite element model. Different groutgrouting machine,grouting pressure are employed in different geological conditions, The mechanical parameters in strengthened region differs largely, it makes difficulties in finite element analysis when modeling.Mechanical parameters in strengthened region are obtained by geotechnical engineering displacement back analysis, the optimization design technology APDL in ANSYS is used. Construction Dynamic analysis are carried out by ANSYS to make sure of the feasibility of the construction program when the obtained parameters are applied.The tunnel in Beijing city in the section of Jing-Shi is taken for example to be researched by geotechnical engineering displacement back analysis, the tunnel is part of South to North Water transfer project, it is used for emergence water-supply project. The following subjects are studied:1.Mechanical parameters in the strengthened region are back-analyzed by geotechnical engineering displacement back analysis theory and mathematics principle of underground engineering optimization back analysis, otherwise, the optimization design module in ANSYS is utilized. The mechanical parameters of strengthened region of the tunnel in Beijing city in the section of Jing-Shi are back-analyzed by those theory mentioned above.2. "life and death" element of the South-North Water Transfer Jingshi of South to North Water transfer project (Beijing) West Fourth Ring culvert in the ditch across the River bridge on the 16th under the pile and wear Fushilu No.3 Channel Bridge construction of the two major areas using the anti-parameter analysis of the actual working conditions for dynamic analysis. The influence to bridge pile and channelshould be surveyed before construction, the extent and domain of the influence and the area which would be dangerous should be know clearly, also, the construction measurement should be proposed.3 Finally, it generalizes the research conclusion, and the prospect of displacement back analysis is mentioned.