Development Character Of Pusiluo Debris Flow Gully In Jinping Hydropower Station And Its Negative Influence On Rpoject

Jinping hydropower station Class one of is the large-scale hydroelectric project planned and exploited in the lower reach of Yalong River, which has been constructed at the key period presently. Pusiluo gully locates the underground workshop's infall position of the upriver side of Jinping hydropower station's dam shoulder, in whose region at one time some various large-scale debris flow activities break out in history; and some solid matter has been dashed out from the gully, especially, the activity of debris flow happened on July,2004 was the most large-scale one in the recent ten years. In order to prevent debris flow from bring negative influence to the infall position of undergroud workshop in the hydropower station, the devisers have proposed the project including check dam and tunnel guiding waterflow on the left bank in the positiion, where the height above sea level of Pusiluo gully bottom is 1,900m. Obviously, investigating the nature, character and formation conditions of Pusiluo gully debris flow, predicting the scale of its bursting, estimating its risk appraisal, evaluating the its harzad degree on the above-mentioned position of project and bringing forward reciprocal prevetion and control of project are indispensable.The thesis introduces the development background of the Pusiluo gully debris flow firstly; secondly, formulates its development character including gulch character and valley subzone character, and distinguishing the nature of debris flow by analyzing the physical source; according to its onw character, selecting some latest research results of debris flow for the moment, calculates the dynamical parameters of debris flow such as the scale, the velocity of flow, the wallop, the peak value flux, and the total flux etc, and analyzes the generant frequency of debris flow bursting, predicting the scale of debris flow; opting fifteen factors which have the negative influence on the activity of debris flow for the decisive genes, judging the activity of Pusiluo gully debris flow with quantitative synthesis appraisal principles; adopting analytic approach of gray correlation and combining seven debris flow gullies such as Jiangjia gully etc, calculating the relativity of Pusiluo and Jiangjia gullies, estimating its dangerous range, calculating the hazard degree of Pusiluo gully debris flow with the latest and improved calculation formula for single debris flow gully, the two methods applying to research the same question is accordant by and large; at last, basing on the gulch character analyzed and the results calcualated, to the different design frequency, predicting the deposit extent of debris flow's solid matter which dashed out from Pusiluo gully only one time, and bringing forward the corresponding preventin and control of debris flow through discussing the difficult position of check dam devised.