Construction Technology of one Unsymmetrical Loaded Deep Foundation Pit Adjacent to Expressway Subgrade

Abstract:

One deep foundation pit in Hefei urban rail transit project is adjacent to the existed expressway subgrade, it's in the unsymmetrical loaded state. The control of foundation pit deformation and the safety of subgrade must be strictly ensured. Based on it, the design scheme of supporting system, the construction processes of earth excavation, top beam, concrete support and steel support was introduced. The horizontal displacement of fender piles and the settlement of subgrade was monitored. The field monitoring results indicate, there exists a great difference between the retaining structure deformation under the action of unsymmetrical load and the deformation under the action of symmetrical load, the horizontal displacement of fender piles on the side of subgrade is bigger than the other side, the upper pile appears to be a "drift" towards the lower-load side; although the absolute value of horizontal displacement of fender piles and settlement of subgrade seems to be a big number, the relative value is small compared to the whole length of fender pile and expressway, meeting relevant standard requirements. The deep foundation pit and expressway kept safe and stable in the all periods of construction, no one accident was occurred during that time. Thus, it can be seen that this construction technology is effective in controlling the deformation during excavation, which can provide a reference for similar projects in design and construction in the future.

• Periodical: Advanced Materials Research (Volumes 919-921)
• Pages: 1411-1415
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.919-921.1411
• Online since: April 2014
• Authors: Bo Liu*, Pei Sheng Xi
• Keywords: Adjacent to Expressway, Construction Technology, Deep Foundation Pit, Field Monitoring, Unsymmetrical Load

References

[1] Zhang XM, Shi YF, Zhang ZL, et al. Dynamic response of enclosure structure of an unsymmetrical loaded foundation pit under train induced dynamic load. Journal of Vibration and Shock 2012; 31(20): 103-109 (in Chinese).

[2] Shi YF, Yang XJ, Bai W, et al. Analysis of field testing for deformation and internal force of unsymmetrical loaded foundation pit's enclosure structure close to railway. Chinese Journal of Rock Mechanics and Engineering 2011; 30(4): 826-833 (in Chinese).

[3] Pang XC, Liu GN, Chen XS, et al. Design and calculation of multipropped retaining structures for asymmetrically loaded deep excavation. Building Structure 2010; 40(7): 106-108 (in Chinese).

[4] Zhang HL, Yang JS, Zhang GL, et al. Application of long-range real-time monitoring system in unsymmetrical loading deep excavation. Transducer and Microsystem Technologies 2010; 29(10): 132-134 (in Chinese).

[5] Zhang HL, Zhang GL, Yang JS. A case history of the excavation of deep foundation pit adjacent to railway. Geotechnical Special publication ASCE 2011; No. 221: 10-16.

DOI: 10.1061/47632(411)2

[6] Liu JQ, Tian ZQ, Lin ZB, et al. Numerical analysis on stability of foundation pit at foot of high slope. Tunnel Construction 2011; 31(3): 294-300 (in Chinese).

[7] Xu Y, Feng RL, Wu YH. Design and analysis of the support structure for metro station unsymmetrical loading pit. Urban Mass Transit Information 2012(9): 43-48 (in Chinese).