Long-term settlement calculation of soft soil foundation undertraffic load based on mechanical-empirical model(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2021年5期
- Page:
- 1-10
- Research Field:
- 道路工程
- Publishing date:
Info
- Title:
- Long-term settlement calculation of soft soil foundation undertraffic load based on mechanical-empirical model
- Author(s):
- XU Linrong; CHEN Yunhao; SHANG Yonghui; FENG Duo; DING Kui
- （1. School of Civil Engineering, Central South University, Changsha 410075, Hunan, China； 2.NationalEngineering Laboratory for Construction Technology of High Speed Railway, Central South University,Changsha 410075, Hunan, China； 3. School of Civil Engineering and Architecture,Huanghuai University, Zhumadian 463000, Henan, China)
- Keywords:
- road engineering; soft soil foundation; traffic load; cumulative plastic strain; dynamic and static deviatoric stress; intensity weakening; longterm settlement calculation
- PACS:
- -
- DOI:
- -
- Abstract:
- To reasonably characterize the influence of various factors on the cumulative plastic strain of soft soil under the cyclic action of traffic load, and effectively predict the settlement of soft soil foundation caused by vehicle load during the operation period, based on summarizing the typical dynamic triaxial test of saturated soft clay in Shanghai, and on the basis of fully measure the effect of dynamic and static deviatoric stress coupling effect, the definition of coupling stress level was given, the parameter χ that reflect the dynamic and static deviatoric stress the degree of their influence, in order to strength weakening of soft clay under the influence of cyclic loading model to correct the indexation. By introducing the limit value of softening index, the concept of modified coupling stress level was proposed, and the cumulative plastic strain model of soft soil was established, which comprehensively reflected the influence of coupling effect of static and static deviator stress, consolidation confining pressure, soil structure, strength weakening and cyclic loading times. Based on this model, the longterm settlement of soft soil foundation induced by traffic load was calculated, and the calculated results were tested with the measured data of Shenjiahu (ShanghaiJiaxingHuzhou) Expressway settlement. The results show that the description of the coupling stress level has uniform applicability in the isotropic and biased consolidation state, through the parameter analysis of the strength weakening model and the cumulative plastic strain model. The calculation results of longterm settlement of Shenjiahu Expressway show that the plastic deformation of shallow surface layer is the most significant. There is a slight difference between the theoretical calculation curve and the measured fitting curve in the initial operation period, and the difference between them gradually weaken after one year of operation, and maintain a strong consistency in the later period.With the increasing of operation years, the settlement gradually tends to be stable. The estimated cumulative settlement of soft soil foundation reaches 128 mm in 550 d after operation, and the relative error is only 1.68% compared with the measured data, indicating that the model is reasonable and reliable. 7 tabs, 11 figs, 28 refs.
Last Update: 2021-09-30