Papers by Author: Wei Gong Chen

Abstract: As an exploration and extension of load/unload response ratio theory, unload/ load response ratio theory (ULRR for short) is introduced firstly, and the relationship between ULRR (Y′) and elastic modulus (E for short) is obtained. Based on the basic theory of damage mechanics,the relationship between ULRR and damage variable (D for short) is set up and analyzed with the relationship between E and D. The unloading and loading experiments on a two-story structure carried out in the University of Naples in Italy are introduced;and calculated damage variable is compared with that calculated by Zhang Langping who put forward Weibull distribution as random distribution function. The results show that damage variable of the structure keep highly consistent with calculations of these two methods. Therefore, the relationship between Y′and D provides a new approach to a health assessment to catastrophic failure of large-scale structures and prediction of engineering.

Abstract: A lot of data indicates that rainfall has always played the very important role in landslide triggering. The paper discusses rainfall as a dynamic parameter in term of the load/unload response ratio theory, using the Xintan landslide as a case study. Analysis of the available data indicates that the occurrences of landslides in this region are controlled by rainfall, whose intensity and rainfall processes are the most important dynamic factors in determining the stability of slopes. Therefore, the relationship between rainfall and the movement of typical landslides has been specifically analyzed for the Xintan landslides by using the loading/unloading response ratio parameter of rainfall. The result of this study indicates that the mutation of the loading/unloading response ratio of rainfall of the Xintan landslide in the Three Gorges Reservoir regions, China occurred just before their destabilization, which shows that the loading/unloading response ratio of rainfall and its changing feature can be taken as a precursor for the landslides induced by rainfall.

Abstract: Debris landslide is a widely distributed and its hazard is huge and hard to forecast with traditional method. Instability drivers of the debris landslide and mechanism were systematically analyzed in this paper. And on that basis, the theory of unload-load response ratio was proposed to forecast the landslide's stability. In the view of system dynamics, the unload-load parameter and unload-load response parameter were singled out and the feasibility was able to build up analyzed, and then, the model of unload-load response ratio was built. As an example, the model was used to analyze and calculate the Xintan typical debris landslide. The results were showed. The steady state reflected by the timing curve of the unload-load response ratio was consistent with the landslide's actual status, when Y'→0, the overall unstability of landslide would appear. That showed it was available to use the unload-load response ratio to forecast landslide's deformation stage and as a criterion of landslide instability.