Monitoring And Analysis Of A Deep Circular Foundation Excavation

Deep foundation pit engineering is one of the difficult problems by geotechnical engineers. How to effectively control it's deformation and make it safe and economical are the task that people always probe. The earth pressure on the circular retaining structure is reduced by the soil arching effect, and the high compression resistance character is fully used. As a result, more and more circular retaining structures are applied in the excavations.The current studying situation of monitoring and analysis of the deep pit are reviewed. And the soil's deformation mechanism during excavation are explained as well.The North anchorage of Guangzhou Huangpu Bridge over Pearl River is a very important deep round pit with depth of 30 meters. A ring diaphragm wall accompanied with varied-thickness inner concrete lining acted as the bracing system. After the brief presentation of the engineering geological condition of the site and monitoring scheme, this paper presents monitoring data including the lateral displacement of diaphragm wall, the horizontal and vertical displacement on the top of itl, the pore water pressure and earth pressure of the soil behind it, the steel stress in it, inner transverse stress and their analysis. The results show that the round diaphragm wall of rock-socketed can control the deformation of foundation excavation effectively.