Studies Of Construction Technics And Construction Monitoring On Shallow Underground Excavation Method In Hangzhou

Along with Hangzhou urban development, the traffic pressure in the downtown area has become heavier and heavier. In order to ease this status, 9 pedestrian overpasses and 7 pedestrian underpasses had been built up in Hangzhou city proper up to the end of 2005, while the "Planning for Main Road Pedestrian and Non-motorized Vehicle Cross-street Facilities in Main Urban Area of Hangzhou City" had been worked out at the beginning of 2006. In addition to the pedestrian cross-street facilities under current status, the planning has covered 5 pedestrian overpasses and 17 pedestrian underpasses to be built, as well as 61 places of pedestrian cross-street facilities required for further clarification in depth and 19 places of cross-street facilities to be connected with rail tracks, and 102 places of pedestrian cross-street facilities have been planned in total.The construction of more and more urban underpasses has been implemented in city area, and as the construction sites are frequently located in the busy traffic areas, shallow underground excavation method is applied for underpass construction on more occasions. The geological condition in the city zone of Hangzhou is complicated, the construction environment is bad, and the real-time monitoring dynamic construction must be combined in use. It has important engineering value and theoretical significance to carry on construction monitoring analysis and research on shallow underground excavation method for pedestrian underpasses in the city zone of Hangzhou.The paper has discussed and summarized the key points of construction process and construction monitoring on the shallow underground excavation method for urban pedestrian underpasses, based on literature consultation. The distortion and stress characteristics of the surrounding wall and the supporting structure have been analyzed, in a combined consideration about the construction monitoring on Hangzhou Wulin Square Underpass and Zhalongkou Underpass, to study the patterns of ground surface settlement, arched vault settlement, clearance horizontal convergence, and surrounding rock soil pressure along with time change, during the construction of shallow underground underpasses, to compare the monitoring data under different supporting conditions for the same underpass and the monitoring data under different geological conditions with the same construction method, so as to derive relevant conclusions and suggestions, able to provide references for design and construction of similar projects.