Analysis of low embankment built on artificial hard crust with large deformation theory(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2017年02期
- Page:
- 18-25
- Research Field:
- 道路工程
- Publishing date:
Info
- Title:
- Analysis of low embankment built on artificial hard crust with large deformation theory
- Author(s):
- ZHANG Zong-tao; ZHANG Hong-liang; LI Zhi-gang; CHENG Feng-lei
- 1. School of Highway, Chang’an University, Xi’an 710064, Shaanxi, China; 2. Rizhao Transportation Development Group Co. Ltd., Rizhao 276800, Shandong, China
- Keywords:
- road engineering; soft foundation; low embankment; artificial hard crust; large deformation theory
- PACS:
- U414.75
- DOI:
- -
- Abstract:
- The instability and large deformation of soft foundation occur frequently with pavement cracking when low embankment is constructed on soft foundation, and artificial hard crust is usually used to solve this problem. At present, corresponding design parameters and treatment methods of artificial hard crust on soft foundation have not been deeply studied, and most of the methods come from engineering experience and laboratory experiment. To optimize the design of artificial hard crush for the treatment of soft foundation and put forward corresponding value range of design parameters for artificial hard crust, finite element model of road on soft foundation was established by using finite element software ABAQUS based on large and small deformation theories. Influence degree of two soft foundation models on the results were compared, and finite element model which could reasonably simulate soft foundation was chosen. Then effects of modulus, thickness, width of artificial hard crust on mechanical response and soft foundation were analyzed. Finally, value range of design parameters for artificial hard crust on soft foundation were recommended. The results show that when the low embankment is constructed on soft foundation containing artificial hard crust, the shear failure caused by low bearing capacity, large settlement deformation of soft foundation and pavement early cracking caused by low equivalent subgrade modulus. Compared with expanded Drucker-Prager model, when porous medium elasticity model based on large deformation theory is used to simulate soft foundation, the surface settlement of pavement increases by 45.1%, while the additional stress decreases by 4.9%, which proves that large deformation theory is more reasonable compared to small deformation theory for simulating soft foundation. Moreover, as modulus, thickness and width of artificial hard crust increase within a proper range, stress and displacement of soft foundation decrease while additional stress of pavement increases. The ranges of modulus and thickness of artificial hard crust are recommended from 150 to 300 MPa and 1 to 2 m respectively, and the width increases by 1 m more than the width of subgrade slopes on each side.
Last Update: 2017-04-07