Xue D.,Chengdu University of Technology |
Li T.,Chengdu University of Technology |
Wei Y.,China Railway Second Engineering Group Co. |
Gao M.,Chengdu University of Technology
Environmental Earth Sciences | Year: 2015
This paper presented the reactivated mechanism of Badu landslide according to site investigations, monitoring, finite element and limit equilibrium analyses. Finite element analysis incorporating a stability analysis with the finite element stress-based method revealed a large railway cut triggered a localized slide in the upper part of Badu landslide rather than a global failure, and piles in three rows were effective in stabilizing the reactivated zone. Monitoring results and the limit equilibrium analysis showed that the landslide underwent multi-instabilities rather than a global failure due to a rise in groundwater table in rainy season. The mechanism of reactivated Badu landslide was finally proposed, i.e., “grading creeping-sliding” mechanism, which helped designers to propose the most suitable mitigation measures to stabilize the landslide. © 2014, Springer-Verlag Berlin Heidelberg.
Chen G.-Q.,Chengdu University of Technology |
Li T.-B.,Chengdu University of Technology |
Zhang Y.,Chengdu University of Technology |
Fu K.-L.,China Railway Second Engineering Group Co. |
Wang D.,China Railway Second Engineering Group Co.
Yantu Lixue/Rock and Soil Mechanics | Year: 2013
Thermal effect of brittle failure for hard rock tunnel under high geostress and high ground temperature need to be studied urgently; and the calculation analysis related to brittle failure rarely considers thermal effect. Based on the method of thermal-brittle-fine mechanical calculation, the thermal effect of excavation unloading for hard rock tunnel is calculated by using a new constitutive model reflecting the brittle failure of hard rock; and the energy release rate index is also analyzed. Taking the rock pillars of APSE tunnel in Sweden for example, the mechanical response of tunnel excavation is analyzed under different ground temperatures. Then the damage degree of surrounding rock is analyzed under the action of temperature loading. The failure zone, energy release value and stress index are compared under different ground temperatures. The result shows that increased temperature will strengthen the brittle failure because temperature will make rock mass to generate additional thermal stress. The method of thermal-brittle-fine mechanical calculation can reasonably describe the progressive failure process of hard rock. The proposed method reveals the thermal effect of brittle failure for deep hard rock tunnel, and could benefit the stability evaluation for deep hard rock tunnel under high ground temperature.
Chen G.,Chengdu University of Technology |
Li T.,Chengdu University of Technology |
He Y.,Chengdu University of Technology |
Jiang L.,China Railway Second Engineering Group Co. |
And 2 more authors.
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2013
The failure mechanism of tunnel is more complex under the high geostress and high ground temperature action for deep hard rock tunnel. Loading-unloading triaxial tests on granite under different temperatures were carried out. The complete stress-strain curves of rock, mechanical parameters of rock, and macro failure types under different temperature conditions were analyzed in detail. The results show that there is a temperature threshold value of 60°C-100°C. The failure is from ductile to brittle with the temperature increase if the temperature does not exceed the threshold value. Temperature enhanced the brittle damage of hard rock. Shear is the dominant failure mode with the temperature increase. Then based on the test, thermo-mechanical coupling calculation was carried out. The thermal effect of excavation unloading for hard rock tunnel was calculated by using a brittle constitutive model and energy release rate index. The mechanical response to tunnel excavation was analyzed under different ground temperatures. The plastic zone, stress index and energy release value were compared quantitatively under different ground temperatures. The calculation showed that temperature increase would make rockburst intensity increase, and shear zone increase. The result of calculation and test data is consistent, and the analysis could benefit the understanding of brittle failure under high ground temperature.