Influence of subgrade modulus on fatigue cracking damage of cement concrete pavement under traffic load
-
摘要: 基于有限元软件KENSLABS, 构建了水泥混凝土路面轮载损伤计算模型, 引入地基季节调整系数与零养护疲劳准则, 分析了土基模量整体削弱对路面疲劳开裂指数的影响, 探讨了当量轴载系数与多轴通过一次的计算次数对土基模量的依赖性, 研究了不同土基模量下板厚、水泥混凝土抗弯拉强度、单轴轴重、单轴每日重复作用次数等核心路面设计参数与路面开裂指数的关系。研究结果表明: 水泥混凝土路面疲劳开裂指数随着地基季节调整系数的减小而增大, 增大速度随地基季节调整系数的减小而加快, 当地基季节调整系数从1.0减小为0.8和从0.4减小为0.2时, 在单轴、双轴和三轴荷载作用下, 路面开裂指数分别增大了2.8、2.9、1.5倍和49.8、269.0、1 351.4倍; 当量轴载系数与多轴通过一次的重复计算次数受到板厚与土基模量的影响, 在土基模量为60 MPa, 板厚为15cm或35cm时, 单轴荷载比双轴荷载更易产生损伤, 双轴荷载比三轴荷载更易产生损伤, 在土基模量为20MPa, 板厚为15cm时也是如此, 但在土基模量为20MPa, 板厚为35cm时, 结论则与前相反; 水泥混凝土路面疲劳开裂指数随着面板厚度、水泥混凝土抗弯拉强度、单轴轴重、单轴每日重复作用次数而改变的幅度与土基模量直接相关, 当土基模量为20、60 MPa时, 面板厚度从21cm增加到25cm, 疲劳开裂指数分别减小1.18×10、1.18×10-2, 当混凝土抗弯拉强度从4.0 MPa增大到4.4 MPa, 疲劳开裂指数分别减小1.28、2.20×10-3, 当单轴轴重从80kN增大到160kN时, 疲劳开裂指数分别增大5.48、7.36×10-3, 当单轴荷载每日重复作用次数从50增加到90时, 疲劳开裂指数分别增大2.05×10 -1、5.07×10-4; 增设厚度为15cm的水泥稳定基层后, 设定工况下的路面疲劳开裂设计寿命增加3.42年; 在提高土基模量的同时, 宜优先考虑适当增加板厚, 严禁超载, 设置水泥稳定基层等措施, 可以控制水泥混凝土路面受轮载作用的疲劳开裂破坏。Abstract: Based on finite element software KENSLABS, the damage calculation model of cement concrete pavement under traffic load was established.Based on the foundation seasonal adjustment factor and the zero-maintenance fatigue criterion, the influence of overall decrease of subgrade modulus on the fatigue cracking index of pavement was analyzed, the dependence of equivalent axle load factor and number of repetitions for one passage of multiple axles on subgrade modulus was discussed, and the relationships between the cracking index of pavement and the core parameters of pavement design including slab thickness, modulus of rupture of cement concrete, uniaxial load weight, repeated times of uniaxial load in one day were studied.Analysis result indicates that when the seasonal adjustment factor of foundation decreases from 1.0 to 0.8 and from 0.4 to 0.2, the growth rates of cracking index of pavement are 2.8, 2.9, 1.5 and 49.8, 269.0, 1351.4 under the uniaxial load, biaxial load, triaxial load, respectively, so the fatigue cracking index of cement concrete pavement increases with the decrease of seasonal adjustment factor of foundation, and the smaller the seasonal adjustment factor of foundation is, the faster the increase of the fatigue cracking index is.When the subgrade modulus is 60 MPa and the thickness of slab are 15 cm or 35 cm, the uniaxial load is more destructive than the biaxial load, and the biaxial load is more destructive than the triaxial load.The same is true for 15 cm slab with a subgrade modulus of 20 MPa.But for 15 cm slab with a subgrade modulus value of 60 MPa, the order is reverse.So the equivalent axle load factor and the number of repetitions for one passage of multiple axles are affected by slab thickness and subgrade modulus.When the subgrade modui are 20 MPa and 60 MPa and the thickness of slab increases from 21 cm to 25 cm, the fatigue cracking indexes decrease by 1.18×10 and 1.18×10-2, respectively.When the modulus of rupture of cement concrete increases from 4.0 MPa to 4.4 MPa, the fatigue cracking indexes decrease by 1.28 and 2.20×10-3, respectively.When the uniaxial weight increases from 80 kN to 160 kN, the fatigue cracking indexes increases by 5.48 and 7.36×10-3, respectively.When the repeated times of uniaxial load in one day increases from 50 to 90, the fatigue cracking indexes increase by 2.05×10 -1 and 5.07×10-4, respectively.So when the fatigue cracking index of cement concrete pavement varies with slab thickness, modulus of rupture of cement concrete, uniaxial weight, repeated times of uniaxial load in one day, there is a direct relationship between its ranges and subgrade modulus.When 15 cm cement stabilized base is added, the fatigue cracking design life of pavement increases by 3.42 years under designing working condition.At the same time improving subgrade modulus, some measures including appropriately adding slab thickness, strictly forbidding overloading, setting cement stabilized base should be taken into account preferentially to control the fatigue cracking damage of cement concrete pavement under traffic load.
-
图 3 水泥混凝土路面轮载损伤分析的有限元模型
Figure 3. Finite element model analyzing damage of cement concrete pavement under traffic load
图 5 不同地基季节调整系数下路面的开裂指数
Figure 5. Cracking indexes of pavement under different seasonal adjustment factors of foundation
图 6 单轴荷载下水泥混凝土面板应力分布
Figure 6. Stress distributions of cement concrete slab under uniaxial load
图 7 双轴荷载下水泥混凝土面板应力分布
Figure 7. Stress distributions of cement concrete slab under biaxial load
图 8 三轴荷载下水泥混凝土面板应力分布
Figure 8. Stress distributions of cement concrete slab under triaxial load
图 10 水泥混凝土抗弯拉强度对路面开裂指数的影响
Figure 10. Influence of flexural-tensile strength of cement concrete on cracking index of pavement
图 11 单轴轴重对路面开裂指数的影响
Figure 11. Influence of uniaxial load on cracking index of pavement
图 12 单轴每日重复作用次数对路面开裂指数的影响
Figure 12. Influence of repeated times of uniaxial load in one day on cracking index of pavement
表 1 各时期中不同荷载组作用下的路面开裂指数
Table 1. Cracking indexes of pavement in different periods under different axle load groups
下载: 导出CSV
表 2 当量轴载系数和多轴通过一次的重复作用次数
Table 2. Equivalent axle load factors and repetitions of one passage of multiple axles
下载: 导出CSV
-
[1] 覃绮平. 土基回弹模量影响因素及其相关关系研究[D]. 西安: 长安大学, 2005.QIN Qi-ping, Research on effect elements and relevant relationships of subgrade resilience modulus[D]. Xi'an: Chang'an University, 2005. (in Chinese). [2] 柳志军, 刘春荣, 胡朋. 土基回弹模量合理取值试验研究[J]. 重庆交通学院学报, 2006, 25 (3): 62-64. https://www.cnki.com.cn/Article/CJFDTOTAL-CQJT200603016.htmLIU Zhi-jun, LIU Chun-rong, HU Peng. Experimental study on reasonable evaluation of rebound modulus of subgrade[J]. Journal of Chongqing Jiaotong University, 2006, 25 (3): 62-64. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-CQJT200603016.htm [3] 胡梦玲, 余祥宏, 姚海林, 等. 非饱和路基土模量确定方法[J]. 岩石力学与工程学报, 2012, 31 (4): 834-840. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX201204025.htmHU Meng-ling, YU Xiang-hong, YAO Hai-lin, et al. Determination method of modulus of unsaturated subgrade soil[J]. Chinese Journal of Rock Mechanics and Engineering. 2012, 31 (4): 834-840. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX201204025.htm [4] 戴张俊, 余飞, 陈善雄. 淮北平原典型地基土动态变形模量特征及与承载力相关关系研究[J]. 岩石力学与工程学报, 2013, 32 (增1): 2723-2729. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2013S1019.htmDAI Zhang-jun, YU Fei, CHEN Shan-xiong. Research on characteristics of dynamic deformation modulus and its correlation with bearing capacity for typical soil in Huaibei Plain[J]. Chinese Journal of Rock Mechanics and Engineering, 2013, 32 (S1): 2723-2729. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX2013S1019.htm [5] LEUNG G L M, WONG A W G, WANG Yu-hong. Prediction of resilient modulus of compacted saprolitic soils by CBR approach for road pavement subgrade: a re-examination[J]. International Journal of Pavement Engineering, 2013, 14 (4): 403-417. doi: 10.1080/10298436.2012.727993 [6] ZHU Zhan-yuan, LING Xian-zhang, WANG Zi-yu, et al. Experimental investigation of the dynamic behavior of frozen clay from the Beiluhe subgrade along the QTR[J]. Cold Regions Science and Technology, 2011, 69 (1): 91-97. doi: 10.1016/j.coldregions.2011.07.007 [7] 颜利, 李宇峙, 邵腊庚, 等. 沥青路面土基模量季节变化影响分析[J]. 公路交通科技, 2007, 24 (2): 44-47. https://www.cnki.com.cn/Article/CJFDTOTAL-GLJK200702011.htmYAN Li, LI Yu-zhi, SHAO La-geng, et al. Analysis of influence of seasonal variation of subgrade modulus of asphalt pavement[J]. Journal of Highway and Transportation Research and Development, 2007, 24 (2): 44-47. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-GLJK200702011.htm [8] LEE J, JEONG S. Experimental study of estimating the subgrade reaction modulus on jointed rock foundations[J]. Rock Mechanics and Rock Engineering, 2016, 49 (6): 2055-2064. doi: 10.1007/s00603-015-0905-9 [9] KIM J R, KANG H B, KIM D, et al. Evaluation of in situ modulus of compacted subgrades using portable falling weight deflectometer and plate-bearing load test[J]. Journal of Materials in Civil Engineering, 2007, 19 (6): 492-499. doi: 10.1061/(ASCE)0899-1561(2007)19:6(492) [10] PING W V, YANG Zeng-hai, GAO Ze-chuan. Field and laboratory determination of granular subgrade moduli[J]. Journal of Performance of Constructed Facilities, 2002, 16 (4): 149-159. doi: 10.1061/(ASCE)0887-3828(2002)16:4(149) [11] SALOUR F, ERLINGSSON S. Resilient modulus modelling of unsaturated subgrade soils: laboratory investigation of silty sand subgrade[J]. Road Materials and Pavement Design, 2015, 16 (3): 553-568. doi: 10.1080/14680629.2015.1021107 [12] NAZZAL M D, TATARI O. Evaluating the use of neural networks and genetic algorithms for prediction of subgrade resilient modulus[J]. International Journal of Pavement Engineering, 2013, 14 (4): 364-373. doi: 10.1080/10298436.2012.671944 [13] 鲍远骥. 公路土基回弹模量分析与研究[D]. 西安: 长安大学, 2003.BAO Yuan-ji. Analysis and research on subgrade resilience modulus of highway[D]. Xi'an: Chang'an University, 2003. (in Chinese). [14] 周雪铭. 路基含水量对弯沉值的影响[J]. 中南公路工程, 2003, 28 (1): 60-62. https://www.cnki.com.cn/Article/CJFDTOTAL-ZNGL200301019.htmZHOU Xue-ming. Effect of roadbed moisture content on deflection[J]. Central South Highway Engineering, 2003, 28 (1): 60-62. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-ZNGL200301019.htm [15] 时伟. 土基回弹模量对沥青路面的影响及加固层设计研究[D]. 西安: 长安大学, 2007.SHI Wei. Study on soil base's modulus of resilience impacting on asphalt pavement and back-up coat designing[D]. Xi'an: Chang'an University, 2007. (in Chinese). [16] 刘斌. 土基回弹模量对路面结构层的影响分析[D]. 西安: 长安大学, 2013.LIU Bin. Analysis of the influence of the soil base resilient modulus to the pavement layer[D]. Xi'an: Chang'an University, 2013. (in Chinese). [17] 武红娟, 王选仓. AASHTO法中土基模量取值对沥青路面的影响[J]. 长安大学学报: 自然科学版, 2008, 28 (5): 14-17. https://www.cnki.com.cn/Article/CJFDTOTAL-XAGL200805005.htmWU Hong-juan, WANG Xuan-cang. Influence of design value of soil base's modulus in AASHTO on asphalt pavement design[J]. Journal of Chang'an University: Natural Science Edition, 2008, 28 (5): 14-17. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-XAGL200805005.htm [18] 武红娟, 王选仓. 土基模量随季节变化对沥青路面设计的影响[J]. 长安大学学报: 自然科学版, 2008, 28 (4): 7-10. https://www.cnki.com.cn/Article/CJFDTOTAL-XAGL200804003.htmWU Hong-juan, WANG Xuan-cang. Influence of variation of soil base's modulus with season's changing on asphalt pavement design[J]. Journal of Chang'an University: Natural Science Edition, 2008, 28 (4): 7-10. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-XAGL200804003.htm [19] 林小平, 凌建明, 周亮. 路基回弹模量对刚性路面疲劳寿命的影响分析[J]. 武汉理工大学学报: 交通科学与工程版, 2012, 36 (2): 262-265. https://www.cnki.com.cn/Article/CJFDTOTAL-JTKJ201202010.htmLIN Xiao-ping, LIN Jian-ming, ZHOU Liang. Effect analysis of subgrade resilience modulus on pavement fatigue life for rigid[J]. Journal of Wuhan University of Technology: Transportation Science and Engineering, 2012, 36 (2): 262-265. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-JTKJ201202010.htm [20] 吴祖德. 道路土基回弹模量及其在路面结构中的影响[J]. 城市道桥与防洪, 2013 (1): 10-17. https://www.cnki.com.cn/Article/CJFDTOTAL-CSDQ201301006.htmWU Zu-de. Subgrade resilient modulus of road and its influence in pavement structure[J]. Urban Roads Bridges and Flood Control, 2013 (1): 10-17. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-CSDQ201301006.htm [21] BRAND A S, ROESLER J R. Finite element analysis of a concrete slab under various non-uniform support conditions[J]. International Journal of Pavement Engineering, 2014, 15 (5): 460-470. [22] 刘竹君. 板底脱空对水泥混凝土路面接缝传荷及疲劳开裂损伤的影响[D]. 成都: 西南交通大学, 2012.LIU Zhu-jun. The influence of the void beneath slabs of cementconcrete pavement to the load transfer of the joint and fatigue cracking damage[D]. Chengdu: Southwest Jiaotong University, 2012. (in Chinese). [23] 蒋应军, 戴学臻, 陈忠达, 等. 重载水泥混凝土路面损坏机理及对策研究[J]. 公路交通科技, 2005, 22 (7): 31-35. https://www.cnki.com.cn/Article/CJFDTOTAL-GLJK200507008.htmJIANG Ying-jun, DAI Xue-zhen, CHEN Zhong-da, et al. Study on mechanism of cement concrete pavement damage of heavy-duty traffic road and countermeasures[J]. Journal of Highway and Transportation Research and Development, 2005, 22 (7): 31-35. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-GLJK200507008.htm [24] KONRAD J M, LEMIEUX N. Influence of fines on frost heave characteristics of a well-graded base-course material[J]. Canadian Geotechnical Journal, 2005, 42 (2): . -
点击查看大图
图(12) / 表(2)
计量
- 文章访问数: 562
- HTML全文浏览量: 137
- PDF下载量: 534
- 被引次数: 0
