Support mechanism and effect of cutting high slope in expressway reconstruction and expansion projects(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2017年03期
- Page:
- 39-46
- Research Field:
- 道路工程
- Publishing date:
Info
- Title:
- Support mechanism and effect of cutting high slope in expressway reconstruction and expansion projects
- Author(s):
- WANG Da-wei; SHEN Peng
- 1. Key Laboratory for Special Area Highway Engineering of Ministry of Education, Chang’an University, Xi’an 710064, Shaanxi, China; 2. Guangxi Guihai Expressway Group Co., Ltd., Nanning 530021, Guangxi, China; 3. CCCC First Highway Consultants Co., Ltd., Xi’an 710075, Shaanxi, China
- Keywords:
- road engineering; supporting scheme; FLAC3D; high slope; optimization
- PACS:
- U416.1
- DOI:
- -
- Abstract:
- In order to analyze the support mechanism of cutting high slope in road reconstruction and expansion projects and to optimize support scheme, high slope of K1415+200 on the left side of Liunan (Liuzhou to Nanning) Expressway was taken as an example. Firstly, the influence of slope excavation on slope stability was studied by FLAC3D numerical method, then orthogonal experiment was designed to analyze the influence rules of anchor angle, anchor length and anchor space on slope safety factor when using anchor support. Changes of slope safety factor were studied under the working conditions of original slope construction anti-slide pile and excavation of two anterior soil of piles. Monitoring points along height of the slope were set to analyze horizontal and vertical displacement of soil slope in anti-slide pile before and after the construction of anchor cable, and stress of the slope soil was studied by strain increment nephogram. Finally, two support schemes were compared in the aspects of supporting effect, construction difficulty and economy. The results show that the safety factor is less than the code limit value by using the existing reconstruction and expansion project to excavate, so appropriate support measures should be taken. Both setting appropriate anchor angle and increasing anchor length within the effective anchorage depth can improve safety factor of the slope. However, increasing anchor spacing will reduce the safety factor of the slope, and when the spacing is more than 4 m, the sensitivity will be enhanced. Sensitivity of the slope safety factor to the length of anchor is obviously greater than that of angle and spacing of anchor. Slope soil can get better lateral support when using anti-slide pile retaining. At this time, slope safety factor can be improved, and the slope displacement can be reduced further when adding anchor cable, which has less influence on internal force of slope soil. In this project, the support effect, the construction difficulty and the cost are more reasonable when using anchor to reinforce slope.
Last Update: 2017-06-06