Study Of Interaction Of Deep Foundation And Nearby Tunnel Construction

The Changsha Yingpan-Road-tunnel is an important traffic arteries to ease the traffic pressure and enhance the connections between downtown and west block of Changsha. It’s C, D ramps on the east side of Xiangjiang River have very small spacing between the neighboring Chaozong Regency Building Foundation pit. The stress in the common envelope between D ramp open-cut pit and Chao-Zong Regency Building Foundation pit is very complex, construction process would be extremely difficult. It must analyze how those envelope structures are affected and keep their displacement in allowable range to ensure the safety in whole construction process.Two-dimensional elastic-plastic finite element models are established in this article to analysis the interaction of this area. By comparing calculation results with the on-site monitoring measured data, it indicate that the calculation results agree with actual situation roughly.Using the above Finite Element Calculating Models, with the force condition of retaining structure to analysis about the interaction between the C,D ramps and Chao-Zong Re gency pit to discuss the role of soil reinforcement, anchor, and pulling anchorage cable in this project and research from the level of the construction sequence to optimize the constructio n to get the best way of construction sequence to gain some experience for next similar projects.The research in this paper found that:1.When two foundation pits are close to each other carry out construction at the same ti me, soil will forward to the deeper one and greatly reduced the self-stabilization of the soil be tween those two foundation pits. This situation will happen over and over again during the tim e when construction carry out to make cracks form very easily and reducing the integrity oft he soil body.2.Set up the greater withstanding bending moments of the linked beam which is over the surface between those two foundation pits and the concrete cross struts which is inside the fo undation pit to connect to the bored pile between the foundation pit as a role of enclosure to d eformation effect for the whole structure.3.Shallow Tunnels carry out construction in the adjacent of deep foundation pits will ma ke the initial retaining to have an obvious unevenly horizontal displacement, supporting structure is complicated by bending moments. 4.When two foundation pits carry out construction at the same time the middle soil body needed a grouting reinforcement, the benefits of doing this are:first, strengthen the flexural ri gidity and shearing resistance in the soil column to provide security for force system; second, strengthen the connection of those two bored piles to enhance the role of common deformatio n; third, improving the self-stability of the soil body to reduce the load on the retaining pile.5.To optimize the construction sequence of neighboring two Foundation Pits is to carry out construction, this not only can save time but also can effectively control the movement of the surrounding soil body. When using the cross struts which is within the Foundation Pit and the linking beam which is between those two Foundation Pits combined with the retaining str ucture of Chao-Zong Regency architectural Foundation Pit into a whole to share the moment of bored piles and balanced the force on structures to make them work better.