川藏铁路康定—昌都段滑坡堰塞湖减灾对策及桥梁施工新技术研究

发布时间：2018-11-20 18:35

【摘要】：西部山区地势复杂、地震、滑坡、堰塞湖等自然灾害发生频繁,但是相关研究较为薄弱。为保证铁路线路及交通基础建设的安全性,确保灾后生命通道畅通无阻,滑坡事件已成为阻碍和制约川藏铁路建设的一个关键性问题,滑坡堰塞湖灾害链成为在选线设计阶段就应该防控的风险源。同时,川藏铁路康定-昌都段的规划线路经过高寒区,高寒地区气温偏低,全年施工季节短是阻碍当地建设不可避免的自然因素,因此须要尽量缩短现场施工时间。川藏铁路的修建会面临很多的难点问题,由于时间的局限性,本文仅针对以下两个问题进行分析。首先,本文提出了一套堵江危险性评估作业程式,以及各环节建议采用的理论公式。在此基础上以川藏铁路德沙滑坡整治为例,利用ANSYS处理模型网格、FLAC3D三维有限差分软件建立三维滑坡模型,探讨了滑坡稳定性,通过计算贯穿体体积确定入江方量;然后利用经验公式计算滑距、坡体速度、最小堵江量等参数,获得大震情况下可能堵江的预测结论;最后利用推荐公式计算溃口宽度和流量、沿程洪峰流量和水位,预估堰塞湖影响范围,据此提出了线路工程减灾对策。不仅可为研究区线位设计和重大工程布设提供参考,并希望通过范例性研究,推动山区铁路灾害链减灾技术的发展。其次,本文针对高寒地区交通建设中桥梁建设面临的施工期短问题,对构件接缝开裂限制预制混凝土桥梁在高寒地区广泛应用的国际性难题进行了分析研究。本文创新的提出便于快速施工的新型非连续钢筋接缝的概念,对不同接缝参数的5片足尺梁试件进行抗弯承载力试验,得出新型接缝的最优参数;采用拉压杆力学模型方法展开力学结构理论探讨。对研究高寒地区的结构建设、保障高寒地区及抢险救灾工程中的预制混凝土桥梁的长期安全具有非常重要的意义。
[Abstract]:Natural disasters such as earthquake, landslide and dammed lake occur frequently in western mountainous area, but the related research is relatively weak. In order to ensure the safety of railway lines and traffic infrastructure and ensure the smooth passage of life after the disaster, landslide has become a key problem that hinders and restricts the construction of Sichuan-Tibet railway. Landslide dammed lake disaster chain becomes the risk source of prevention and control in the line selection design stage. At the same time, the planning line of Kangding-Changdu section of Sichuan-Tibet railway passes through the high cold area, the temperature in the high cold area is low, and the short construction season throughout the year is the inevitable natural factor hindering the local construction, so it is necessary to shorten the construction time of the site as far as possible. The construction of Sichuan-Tibet railway will face many difficult problems. Due to the limitation of time, this paper only analyzes the following two problems. First of all, this paper puts forward a set of operational procedures for risk assessment of river plugging, and the theoretical formulas suggested for each link. On the basis of this, taking the regulation of Desha landslide in Sichuan-Tibet railway as an example, using ANSYS processing model grid and FLAC3D 3D finite difference software to establish 3D landslide model, the stability of landslide is discussed, and the amount of flow into the river is determined by calculating the volume of penetrating body. Then the parameters such as slip distance, slope velocity and minimum amount of river plugging are calculated by using empirical formula, and the prediction results of possible river plugging in the case of large earthquakes are obtained. Finally, using the recommended formula to calculate the width and discharge of the crater, the discharge and water level of Hong Feng along the track, and to predict the affected area of the lake, the countermeasures for disaster reduction of the railway project are put forward. It can not only provide a reference for the design of line level in the study area and the layout of major projects, but also hope to promote the development of disaster reduction technology of railway disaster chain in mountainous areas through exemplary research. Secondly, aiming at the short construction period of bridge in traffic construction in alpine area, this paper analyzes and studies the international difficult problem that precast concrete bridge is widely used in alpine area. In this paper, the concept of new discontinuous steel joint, which is convenient for rapid construction, is innovated. The flexural bearing capacity test of 5 full-scale beam specimens with different joint parameters is carried out, and the optimum parameters of the new joint are obtained. The theory of mechanical structure is discussed by means of mechanical model of tension and compression bar. It is of great significance to study the construction of structures in alpine areas and to ensure the long-term safety of precast concrete bridges in alpine areas and emergency relief projects.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U216.419.1;U445.4

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