دانلود رایگان مقاله انگلیسی تحلیل دگرگونی شکل خاک غیر اشباع منبسط شونده در طول مرطوب سازی و خشک کردن - اشپرینگر 2018

Experimental observation on unsaturated expansive soils subjected to wetting and drying cycles presents a stabilized limit equilibrium state at the end of the suction cycles. Models developed previously for this behavior introduce a large number of parameters which lead to a time-consuming procedure to calibrate. This paper develops a limit analysis method with the Zarka concept for the mechanical behavior of expansive soils subjected to wetting and drying cycles. The required parameters of the proposed limit analysis method are calibrated by the experimental results obtained for bentonite/sand mixtures subjected to cyclic suction loadings in an odometric test. The comparison between the test results and the model predictions demonstrates the capacity of the proposed method to calculate the limit deformation during suction cycles and simulate the subsequent mechanical behavior of the expansive soils after suction cycles.

Conclusion

In this work, the limit analysis with a linear kinematic hardening is performed to simulate the mechanical behavior of expansive soils subjected to wetting and drying cycles. The limit deformation during suction cycles can be investigated in the transformed internal parameter plane with a rectangular shape for the yield surface. For the proposed limit analysis of unsaturated expansive soils during suction cycles, we emphasize that the parameter 1/h, which depend on A and B, and the parameters κs and (sI − sD) are sufficient to determine the final limit state. It is important to determine this limit equilibrium state because it presents the final mechanical behavior of unsaturated expansive soil subjected to several suction cycles. The calculated limit deformation during suction cycles can be employed in the coupling law to show the influence of suction cycles on the subsequent mechanical behavior. The same model parameters and calibration procedures as the BExM model can be used and a good qualitative match with the experimental results has been obtained.