二级公路混凝土加铺层病害分析及数值研究

发布时间：2018-04-29 02:36

本文选题：水泥混凝土加铺层 + 水泥混凝土板幅划分　；参考：《南华大学》2014年硕士论文

【摘要】：因交通量激增、车辆超载以及公路临近使用年限，旧水泥混凝土路面开始出现各种结构性病害，原有路面的功能难以满足日益增长的交通的需要，同时也会造成行车安全等问题。为恢复路面的功能，通常在旧水泥混凝土路面上加铺沥青面层或水泥混凝土面层，在旧水泥混凝土路面上加铺沥青面层的研究及建设较多，而加铺水泥混凝土面层的研究相对较少。因此在旧水泥混凝土路面上加铺水泥混凝土面层的设计及施工略有不足，从而造成加铺层过早出现病害，影响公路运营时的正常使用。湖南G322公路（衡南三塘-祁东白地市段）路面改建时，便是在旧水泥混凝土路面上铺筑水泥混凝土加铺层。加铺层宽度11m，采用两幅板块（5.5m+5.5m）及三幅板块（4m+3m+4m）进行施工。在运营过程中，两幅板块的水泥混凝土加铺层距离路面边缘2.0-2.5m产生纵向裂缝，而三幅板块的加铺层中，常规长度为5m的混凝土板产生的病害却很少，仅局部10m过长的板块出现横向裂缝。通过ABAQUS建模分析表明，两幅板的加铺层温度应力较大以及对路基不均匀变形的适应性较差，可能是造成纵向裂缝的主要原因；三幅板局部10m长度的混凝土板出现横向裂缝，主要是板块长度过长，在温度和车辆荷载综合作用下导致。因此，采用长度为5m的三幅板加铺形式是可行的。文中针对三幅板加铺形式，，分别设定方铺方案B（4m+3m+4m）、加铺方案C（3.5m+4m+3.5m）、加铺方案D（3m+5m+3m）。通过有限元分析表明，纵缝不宜设置在车辆行驶轮迹附近；水泥混凝土板宽度应为4m左右，较宽的水泥混凝土板宜布置在路面中间，较窄的水泥混凝土板布置到路面外侧，可以减少温度与车辆荷载叠加的综合应力，从而提高水泥混凝土加铺层的疲劳寿命。加铺方案C各项性能指标较好，为推荐加铺方案。通过对其板厚进行分析，若将路肩处的基层及路基进行补强，在标准轴载下加铺层厚度宜为25cm，考虑到车辆超载，可将加铺层厚度设置为28cm。
[Abstract]:Due to the rapid increase in traffic volume, overloading of vehicles and the approaching service life of the highway, the old cement concrete pavement began to appear various structural diseases, and the function of the original pavement could not meet the increasing traffic needs. At the same time, it will also cause traffic safety and other problems. In order to restore the function of the pavement, the asphalt or cement concrete pavement is usually added to the old cement concrete pavement, and the research and construction of the asphalt surface on the old cement concrete pavement is more than that on the old cement concrete pavement. However, the study of cement concrete surface layer is relatively less. Therefore, the design and construction of overlay cement concrete surface on the old cement concrete pavement is slightly insufficient, which causes premature disease of the overlay and affects the normal use of highway operation. When the road surface of Hunan G322 highway (Hengnan Santang-Qidong Baidi city section) is rebuilt, the cement concrete overlay is laid on the old cement concrete pavement. The width of the overlay is 11m, which is constructed with two plates (5.5m 5.5m) and three plates (4m 3m 4m). In the course of operation, the cement concrete overlay of two plates produces longitudinal cracks from the edge of the road surface 2.0-2.5 m, but among the three plates, the concrete slab with normal length of 5m produces few diseases. Only local plates with 10 m long have transverse cracks. The results of ABAQUS modeling and analysis show that the temperature stress of the overlay and the adaptability to the uneven deformation of the subgrade may be the main causes of the longitudinal cracks, and the transverse cracks appear in the concrete slabs with local length of 10 m in three slabs. The main reason is that the plate length is too long, which is caused by the combined action of temperature and vehicle load. Therefore, it is feasible to use three panels with length of 5m. In this paper, according to the three overlay forms, the plan of square paving is set up respectively, the plan of square paving is 4m 3m 4m / m, the scheme of overlay is 3.5m 4m 3.5m / m, and the scheme of overlay is 3m m ~ 3 m / m, respectively. The finite element analysis shows that the longitudinal joint should not be set near the wheel track of vehicle, the width of cement concrete slab should be about 4m, the wider cement concrete slab should be arranged in the middle of the pavement, and the narrower cement concrete slab should be arranged outside the pavement. The fatigue life of cement concrete overlay can be improved by reducing the combined stress of temperature and vehicle load. The overlay scheme C has better performance index, and it is recommended as the overlay scheme. Through the analysis of the plate thickness, if the base and roadbed at the road shoulder are strengthened, the overlay thickness under the standard axle load should be 25 cm, considering the overload of the vehicle, the overlay thickness can be set to 28 cm.
【学位授予单位】：南华大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U418

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