Study Of Excavating And Supporting During The Construction Of Softrock Highway Tunnel

Based on the numerical analysis method and the construction technology, as well as monitoring measurement, the decision of gray optimal theory and the monitoring theory, with an example of tunnel project, the excavating and supporting during tunnel construction of soft rock highway tunnel are studied. The study work and its feature may be summarized as follows:1) Thesis firstly gives clear definition and classification of soft rock. It gives analysis on geologic and engineering characters of soft rock, and the failure causes of soft rock tunnel is deeply systemic and whole discussed.2) According to characters of soft rock tunnel, The countermeasure and mechanism of excavating and supporting is deeply systemic and whole discussed. The heading and bench method is considered has more strongpoint by analyzing excavation methods with the decision of gray optimal theory during soft rock highway tunnel construction, and it can solve some construction problems on soft rock as fault, soil flow, gushing water etc, also quality and time limit for a project can be insured. It can be controlled for supporting by the flexible support cross-section of the combinational selection with sprayed concrete and grid steel support after excavation. Thesis also brings pertinence measures as built-up temporary inverted arch in bottom section and pipe roof protectionon and locking rock bolts etc on tunnel unfavorable geology in order to obtain the aim of controlling deformation during tunnel construction.3) According to the numerical simulation of characters of repress-entative excavating and supporting, the relation among the variety of plastic range, internal force of preliminary support, deformation of cavern, progressing of excavating settlement of arch crown is studied. The excavating and supporting plan is reasonable from the result of the data processing.4) The excavating and supporting plan is whether reasonable or not...