Study Of Grouting Effect Of High Tower During Shallow-buried Large-span Tunnel Under-passing

Ranked in developing country, our country has complex geologic condition and stretching mountains, so tunnels in our country inevitably pass through shallow fracture zones. With development and construction of high voltage transmission line in our country, some high voltage transmission towers are built on mountains. Limited by geological condition and economic factors, there is no way to build tunnels far away from high voltage transmission towers. Therefore, the way to ensure safety in tunnel construction and stability of tower becomes important since construction of tunnels has to been carried out through shallow fracture zone and high voltage transmission towers.Based on tunneling engineering of Lijiachong, this thesis has adopted surface grouting reinforcement technique to analyze and research the influence of surface grouting to high voltage steel tower and shallow tunnel. The thesis systematically does several researches including grouting theory research on fractured rock, applied research on grouting technique, numerical simulation research on grouting effect of fractured rock, and monitoring and evaluation of grouting effect, with the main findings as follows:1. By looking up relevant documents, the thesis has systematically summarized grouting theory of fractured rock, i.e., fracturing grouting should be used as a major method in grouting in rock mass. This theory has done specific analysis to grouting reinforcement technique of fractured rock.2. Through referring to data of engineering investigation and field grouting experiment, this theory has made design plan and construction process of surface grouting.3. By applying numerical software of Fast Lagrangian Analysis Of Continua In3Dimensions (FLAC3D in short), the thesis does researches on grouting effect of surrounding rock, tunnel and high voltage steel tower. These researches mainly include horizontal and vertical displacement changes of surrounding rock before and after it grouted, settlement of tower foundation, and changes of plastic zone, so on and so forth and it has made a series of significant conclusions.4. After analyzing and evaluating grouting effect through various testing methods and comparing with the result of numerical simulation, the thesis proves that surface grouting has achieved expected effect and it ensures safety and stability of high voltage steel tower.