混凝土预制块路面力学行为及结构设计方法研究

发布时间：2018-01-04 04:38

本文关键词：混凝土预制块路面力学行为及结构设计方法研究　出处：《重庆交通大学》2014年博士论文　论文类型：学位论文

【摘要】：混凝土预制块路面是由单个小尺寸（平面尺寸通常在30×30cm以下）预制块体铺筑在砂垫层上形成的一种特殊路面结构，可采用人工或小型机械辅助施工，其施工灵活且受天气影响小，对环境污染少。预制块路面是一种可以拆卸的“活路面”，块体可以重复利用，且便于就地取材，工程成本及环境压力小。因此，预制块路面是一种既经济又环保的路面结构型式。目前在国外高等级公路中已有应用，但在国内高等级公路中的应用还是空白。预制块路面力学行为及破坏模式与水泥路面和沥青路面有着本质不同，以致在路面结构设计、施工工艺以及养护维修等方面存在较大差异，受适用场合及使用规模的限制，国内缺乏对这种路面结构较为系统深入地研究，目前尚无系统完善的混凝土预制块路面力学行为理论和结构设计方法，对其施工工艺、排水措施、施工质量保证措施、验收标准等也几乎处于空白，因而严重制约了混凝土预制块路面在国内的推广和应用。论文依托云南磨（黑）至思（茅）高速公路建设，针对混凝土预制块路面力学行为、结构设计方法、路面渗水特性及结构防排水设计、路用性能评价、路面施工工艺及质量保证措施等展开系统深入研究。借助室内大型足尺环道试验场，按1:1比例铺筑不同结构组合的预制块路面，试验段考虑了水泥稳定碎石和级配碎石两种基层型式、考虑了细砂、水泥+细砂、乳化沥青砂浆三种接缝材料和2mm、5mm、8mm、10mm四种接缝宽度、考虑了2cm、4cm、6cm三种砂垫层厚度、块体尺寸为29cm×19cm×16cm（长×宽×高），通过调整铺砌方式考虑了16cm、19cm、29cm三种块体结构层厚度。论文取得的主要成果如下： 1、通过承载板试验实测不同结构组合下的预制块路面荷载-弯沉曲线，研究了块体平面尺寸、接缝材料类型、接缝宽度、砂垫层厚度、基层类型等对预制块路面承载力的影响，试验证实了块体层“拱效应”的存在；在荷载作用下块体层表现出“变刚度”的承载力特性，最终揭示了预制块路面承载力机理； 2、提出了临界弯沉、荷载扩散系数、永久变形影响系数等预制块路面结构设计关键参数，通过承载力试验确定了水泥稳定碎石和级配碎石两种基层条件下，不同块体尺寸、砂垫层厚度和不同接缝宽度下的预制块路面临界弯沉值、荷载扩散系数取值范围、永久变形影响系数取值范围； 3、通过室内足尺环道试验测试了在不同标准轴载作用次数下预制块路面平整度和接缝宽度的变化，研究了接缝宽度、砂垫层厚度、块体厚度以及荷载作用次数对预制块路面永久变形的影响规律，建立了混凝土预制块路面永久变形预估模型； 4、通过接缝渗水试验和室内模拟降雨试验研究混凝土预制块路面接缝的渗水特性，研究了接缝材料、接缝宽度对渗水系数的影响，确定了混凝土预制块路面接缝的渗水系数取值范围，建立了预制块路面单位面积（1m2）的渗水量计算方法； 5、运用ANSYS软件建立预制块路面结构的三维有限元模型，针对级配碎石柔性基层和水泥稳定碎石半刚性基层，分析计算了块体厚度、基层厚度、路基模量等对于路表弯沉、基层顶面压应力和基层底面拉应力的影响。计算结果表明路基模量是影响预制块铺面路表弯沉值的最主要因素，块体厚度和基层厚度对于基层底面拉应力有一定影响； 6、建立了以路表车辙深度和基层底面拉应力为控制指标的基于力学的混凝土预制块路面结构设计方法，提出适用于柔性基层的预制块路面车辙深度计算方法和适用于半刚性基层的预制块路面基层底面拉应力计算方法，并给出了相应的轴载换算方法和设计指标容许值范围； 7、提出了适合于高速公路应急车道、服务区的预制块路面典型结构型式，制定了预制块路面施工工艺及质量保证措施，基于论文研究成果指导铺筑了600m混凝土预制块路面试验段，，获得了成功。论文研究成果涉及了预制块路面结构力学行为及结构设计方法、预制块路面结构组合及路用性能评价、预制块路面排水特性及排水结构层设计、预制块路面施工工艺、质量保证措施、质量验收方法以及经济性评价，为推动混凝土预制块路面的应用与发展提供了技术储备。
[Abstract]:Precast concrete block pavement is a single small size (usually in the plane size of 30 * 30cm) is a kind of special precast block paving pavement structure in the sand cushion formation, can use manual or small machinery auxiliary construction, its construction is flexible and little affected by the weather, less pollution to the environment is a precast block pavement. A removable "pavement" blocks can be reused, and easy to use local materials, engineering cost and environmental pressure is small. Therefore, the precast block pavement is a kind of economical and environment-friendly pavement structures. Has been applied abroad in high grade highway in China at present, but in the high grade highway is still blank.
Precast block pavement mechanics behavior and failure mode of cement pavement and asphalt pavement is essentially different, resulting in the pavement structure design, there is a big difference between the construction process and maintenance etc., by the application and use of restrictions on the scale of the domestic lack of the pavement structure in-depth study of systematic structure, there is no perfect system of concrete precast block pavement mechanics behavior theory and method of structure design, drainage measures, the construction technology, construction quality assurance measures, acceptance standards are almost blank, thus seriously restricted the concrete pavement concrete precast block in the domestic popularization and application.
Based on the Yunnan mill (black) to Si (MAO) highway construction, the mechanical behavior of precast concrete block pavement structure, design method, design of anti seepage drainage properties and pavement structure, pavement performance evaluation, pavement construction technology and quality assurance measures are systematically researched deeply. With the help of indoor large full-scale loop test field. According to the proportion of 1:1 precast block pavement paving combination of different structures, considering the test section of cement stabilized macadam and gravel two basic types, the fine sand, fine sand and cement emulsified asphalt mortar, three kinds of joint material and 2mm, 5mm, 8mm, 10mm four kinds of joint width, consider the 2cm, 4cm. 6cm three sand cushion thickness, the block size is 29cm * 19cm * 16cm (length * width * height), by adjusting the paving method considering the 16cm, 19cm, 29cm three kinds of block structure layer thickness.
The main achievements of this paper are as follows:
1, the precast block pavement load - bearing plate test under different structure combination of the deflection curve of block plane size, joint material type, joint width, thickness of sand cushion of base type bearing capacity of precast block pavement, test confirmed that the block layer "arch effect" exists; under the load of block layer shows "bearing capacity stiffness", finally reveals the bearing mechanism of precast block pavement;
2, the concept of critical load deflection, diffusion coefficient, permanent deformation coefficient of precast block pavement structure design of key parameters of cement stabilized macadam and gravel two basic conditions determined by bearing capacity tests under different block sizes, thickness of sand cushion and different seam width of precast block pavement bend under the sink load value, diffusion coefficient range, permanent deformation coefficient range;
3, change width of precast block pavement roughness and joint load at different times under the standard axle test through indoor full-scale loop test, study the joint width, thickness of sand cushion, influence of the number of block thickness and load of precast block pavement permanent deformation, established the pavement concrete precast block permanent deformation estimation model;
4, through the joint penetration test and indoor simulated rainfall experiments on seepage characteristics of precast concrete pavement joint, the joint research materials, effects of joint width on the permeability coefficient, permeability coefficient to determine the range of joint of precast concrete block pavement, a precast block pavement per unit area (1m2) method to calculate the seepage volume;
5, the establishment of a three-dimensional finite element model of precast block pavement structure by using ANSYS software for Graded Macadam flexible base and cement stabilized macadam semi-rigid base, analyzed the block thickness, base thickness and subgrade modulus of the road surface deflection, the surface effect of compressive stress and tensile stress at the bottom of the base. The calculation results show that the modulus of subgrade is the main influencing factor of precast block pavement surface deflections, block thickness and base thickness has a certain influence on the base bottom tensile stress;
6, to establish a road surface rut depth and the mechanics of the precast concrete block pavement structure design method based on base bottom tensile stress control index, precast block pavement base layer bottom tensile stress calculation method of rutting depth of precast block pavement is proposed for the flexible base calculation method and is suitable for semi rigid base, and gives the corresponding conversion method of axle load and design index of allowable value range;
7, a typical structure type for precast block pavement suitable for Expressway Emergency lane and service area has been put forward. The precast block pavement construction technology and quality assurance measures have been worked out. Based on the research results, the 600m concrete precast block pavement test section has been paved successfully.
The research results of this paper relates to precast block pavement structure mechanical behavior and design method of the structure evaluation of precast block pavement structure and pavement performance, the design of precast block pavement drainage and drainage characteristics of precast block pavement structure layer, construction technology, quality assurance measures, quality inspection and the method of economic evaluation, provides technical reserves for promoting the application of with the development of concrete block pavement.

【学位授予单位】：重庆交通大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：U416.2

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