中文摘要：

泥石流灾害是震后危害最大的次生山地灾害，已成为山区防灾减灾和制约当地社会经济发展的突出问题。快速科学地计算震后泥石流淤埋强度和宽度，并在此基础上进行淤埋强度评估，对灾后重大工程选址重建和保障公共安全具有重要意义。以震区汶川县映秀镇红椿沟泥石流为研究对象，在野外考察、试验研究和计算分析的基础上，建立了泥石流淤埋厚度、宽度和强度评估模型，进行红椿沟泥石流淤埋强度评估。研究表明：（1）红椿沟泥石流淤埋厚度评估结果为11．07m，实测结果为10．5m，绝对误差为＋0．57m、相对误差5．1％；（2）泥石流淤埋宽度评估结果为174．66m，实测结果为180．3m，绝对误差为-5．64in、相对误差3．2％；（3）泥石流淤埋强度指数为4．6，为极高强度，具有极高的冲淤能力和危险性；（4）建立的评估模型具有较高的精度，但还需要在野外考察和实验分析的基础上，对重要参数作进一步的修正。研究结果为震区都汶公路及其跨沟桥梁设计施工和防治工程优化设计提供了科学依据和技术支持。

英文摘要：

Debris flow is the most serious and dangerous secondary mountain hazards in Wenchuan earthquake afflicted areas and has become a striking problem of disaster prevention and mitigation and social economic development. It is necessary to calculate the silted width and thickness of debris flow sediment and further to assess relevant sediment magnitude, which may provide a basis for and reference to debris flow mitigation and management as well as key project construction. In this paper, field investigation and experimental analysis were made at Hongchun Gully of Wenchuan, Yingxiu town earthquake-affected area to gain meteorological, hydrological and soil data and debris flow parameters. The models of debris flow silted width, thickness and magnitude were set up and applied to assess the silting up intensity of the Hongchun Gully debris flow. The results show that： （ 1 ） the assessed sitting up thickness is 11.07 m. comparing with the measured thickness, 10.5 m, the absolute error is ＋ 0.57 m, and the relative error is 5. 1%; （2） the assessed sitting up width is 174.66 m. Comparing with the measured 180.3 m, the absolute error is -5.64 m, and the relative error is 3.2% ; （3） the debris flow sitting upmagnitude index is 4.6, which is a extremely high magnitude and risk. （4） the assessment model has high accuracy. The study results could present scientific and technical support to the design and construction Du-Wen highway and its gully-crossing bridges as well as the optimal design of disaster prevention and control project.