桥头跳车搭板在线抬升研究

发布时间：2018-11-10 14:38

【摘要】：我国改革开放之后，公路建设方面得到了快速的进步，尤其是“八五”计划之后，得到了突飞猛进的发展，公路里程增长迅速，相关领域的技术也不断更新。随着经济的稳中有进，社会事业的全面进步，交通运输行业和交通发展改革迈出新的步伐，但是公路交通运输仍是我国的主要运输方式，高速公路在为我国经济发展仍发挥着极其重要的作用。然而，从已交付使用的高等级公路来看，桥头跳车现象非常普遍，己成为改善和提高我国高速公路建设质量的“拦路虎”，也是摆在我们面前的一大技术难题。桥头跳车的危害包括减慢行车速度、影响行车安全、影响车辆运营和增加公路养护费用等。它已成为道路的重要安全隐患之一，因此找到经济有效的防治桥头跳车问题的措施，，提高我国高等公路行车中的安全、舒适和快速等方面的性能，以及增加我国高等级道路的使用年限，对今后我国的道路发展和经济发展都具有及其深远的意义。为了解决桥头跳车问题，减少其地基沉降以及引道自身压缩沉降之外，比较常见的方法是采用桥头搭板防治跳车现象。当前桥头跳车处治措施主要的缺点：被动处治为主、缺乏精确度、影响车辆通行。由于缺乏足够的精度，使得后期治理措施极为繁琐且严重影响车辆通行。本文介绍的注浆方法为粗调、精调两级抬升控制过程；深层注浆加固，浅层注浆抬升，板层螺杆精度抬升注浆填充的三层注浆方式。各级调节、各层注浆相互配合，最终主动完成精确补偿。浅层注浆和深层注浆在整体设计过程中预埋管件，深厚软基处理中的碎石注浆桩改进为墩帽式碎石注浆桩，对地基进一步加固的同时提高地基的承载力和减小沉降。该注浆方法能针对沉降路段不良变形及时有效补偿，把病态消除在萌芽状态，耗时短，操作方便可行，基本是在线抬升，不影响车辆通行。采用ANSYS程序，通过有限元方法分析桥头过渡段软弱地基首先对深厚软基墩帽式碎石注浆桩注浆加固，然后对板底注浆孔初始抬升，最后对板层螺杆注浆填充已达到精度抬升全过程。具体内容包括桥头搭板、墩式碎石注浆桩等组成的复合路基的桩土沉降特性、注浆量，抬升力，抬升值，注浆临界深度。通过ANSYSY建模研究，发现在软土路基加固前，应力主要是在二灰稳定砂砾基层、砂砾垫层及加固区消散，造成该区域土体固结压缩变形，在经过深层注浆加固后，最大应力主要是二灰稳定砂砾基层消散，待沉降逐渐稳定后，进行浅层加固注浆把沉降量控制在一定范围内，以上是粗略调节部分；再通过锚杆精确调节抬升桥头搭板，少量浅层注浆后，恢复沉降变形。因此，把粗调和精调组合使用最终完美的控制了路基的工后沉降，将桥头搭板最终精确完成在线抬升。
[Abstract]:After China's reform and opening up, highway construction has made rapid progress, especially after the "eighth Five-Year Plan", which has been developed by leaps and bounds, the highway mileage has increased rapidly, and the technology in related fields has been constantly updated. With the steady progress of the economy and the overall progress of social undertakings, new steps have been taken in the reform of the transportation industry and traffic development, but road transportation is still the main mode of transportation in China. Expressway is still playing an extremely important role in the economic development of our country. However, from the point of view of the high-grade highway that has been put into use, the phenomenon of jumping at the bridgehead is very common, which has become an obstacle to improving and improving the quality of highway construction in our country, and is also a big technical problem in front of us. The harm of bridgehead jumping includes slowing down the driving speed, affecting the driving safety, affecting the vehicle operation and increasing the cost of highway maintenance and so on. It has become one of the most important hidden dangers of road safety. Therefore, we should find economic and effective measures to prevent and cure the problem of bridge-head jumping, and improve the safety, comfort and speed of our country's higher highway driving, such as safety, comfort and speed, etc. Increasing the service life of our country's high grade roads is of great significance to our country's road development and economic development in the future. In order to solve the problem of bridgehead jumping and to reduce the settlement of foundation and the compression settlement of approach road, the common method is to use bridgehead slab to prevent the phenomenon of jumping. At present, the main shortcomings of the bridge head jumping treatment measures are passive treatment, lack of accuracy, affecting vehicle traffic. Due to the lack of sufficient precision, the later management measures are extremely cumbersome and seriously affect vehicle traffic. The grouting method introduced in this paper is a three-layer grouting method, which includes coarse adjustment, fine adjustment, two-stage uplift control process, deep grouting reinforcement, shallow grouting uplift, plate screw precision uplift and grouting filling. All levels of regulation, each layer of grouting with each other, the final initiative to complete accurate compensation. In the whole design process of shallow grouting and deep grouting, the pipe fittings are preburied, and the gravel grouting pile in the treatment of deep soft foundation is improved into a cap stone grouting pile, which can further strengthen the foundation and increase the bearing capacity and reduce the settlement of the foundation at the same time. The grouting method can compensate the bad deformation in time and effectively, eliminate the morbid state in the budding state, take a short time, operate conveniently and feasible, basically lift on line, and do not affect the traffic of the vehicle. By using ANSYS program, the soft foundation in the transition section of bridge head is analyzed by finite element method. Firstly, the cap type gravel grouting pile with deep soft foundation pier is strengthened with grouting, and then the initial uplift of grouting hole at the bottom of the slab is carried out. Finally, the whole process of plate screw grouting filling has been achieved. The concrete contents include the pile-soil settlement characteristics, grouting quantity, uplift force, lifting value, critical depth of grouting of composite subgrade composed of bridgehead slab, pier-type gravel grouting pile and so on. Through ANSYSY modeling research, it is found that before the soft soil subgrade is strengthened, the stress is mainly in the boulder base, the gravel cushion and the reinforcement area dissipate, resulting in the consolidation and compression deformation of the soil in this area, and after the deep grouting, the stress is strengthened. The maximum stress is mainly dissipated at the base of lime-fly ash stabilized sand and gravel. After the settlement is gradually stabilized, the settlement is controlled within a certain range by shallow reinforcement and grouting, and the above is the rough adjustment part. Then, the lifting bridge head slab is accurately adjusted by the anchor rod, and a small amount of shallow grouting is used to recover the settlement deformation. Therefore, the combination of coarse and fine adjustment controls the post-construction settlement of the subgrade perfectly, and finally completes the on-line uplift of the bridgehead slab.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U445.71

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