斜向预应力混凝土路面数值模拟
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摘要
为研究斜向施加预应力路面的受力特性,通过理论推导由斜向预应力产生的路面板内压应力计算公式,预应力筋的直径、布设角度和间距是影响板内应力的主要因素。建立力学模型,模拟分析预应力筋作用位置、布设间距和角度以及直径大小对路面板应力的影响,结果表明,斜向预应力混凝土路面的锚固区和板角部分区域出现拉应力,但混凝土不会出现开裂;预应力筋布置在1/2板厚偏下是合理的,此时板底压应力大于板顶部,路面板产生负弯矩;预应力布设角度建议范围为25°~45°;考虑到经济性和预应力筋张拉空间,建议预应力筋布设间距最小为0.5 m,预应力筋的布设间距也不能过大,过大易造成路面板应力分布不均匀;可通过调整预应力筋的直径,以得到合理的布设角度和间距。
In order to study mechanical characteristics of the cross-tensioned prestressed concrete pavement,calculation formulas for the average compressive stress caused by prestressing was deduced, diameter,the angle and distance of tendon are the main factors. the finite model of cross-tensioned prestressed concrete pavement was built,the effect of tendon location,the angle of tendon applied and distance between tendon and diameter on stress distribution were also analyzed. The test results show that, because of cross-tensioning,the tensile stress will appear at anchorage zone and corner of the slab,but concrete cracking will not occurr; it is reasonable to place the tendon bellow the mid-depth of the slab,at this depth,the compressive stress of the bottom slab is larger than the top of that,lowering tendon bellow the mid-depth of the slab causes the slab to have an induced negative moment; the recommended angle, at which the tendon applied,should be 25° ~ 45°; the minimum distance between the tendon should be 0. 5 m considering economy and the tensioning space rope,the distance between the tendon should not be too large,otherwise the uneven stress distribution of the slab could be caused; in the event that the calculated distance between tendon is too close or the calculated angle is too large,diameter of tendon should be adjusted to increase compressive stress of the slab and the reasonable distance and angle will be obtained.
In order to study mechanical characteristics of the cross-tensioned prestressed concrete pavement,calculation formulas for the average compressive stress caused by prestressing was deduced, diameter,the angle and distance of tendon are the main factors. the finite model of cross-tensioned prestressed concrete pavement was built,the effect of tendon location,the angle of tendon applied and distance between tendon and diameter on stress distribution were also analyzed. The test results show that, because of cross-tensioning,the tensile stress will appear at anchorage zone and corner of the slab,but concrete cracking will not occurr; it is reasonable to place the tendon bellow the mid-depth of the slab,at this depth,the compressive stress of the bottom slab is larger than the top of that,lowering tendon bellow the mid-depth of the slab causes the slab to have an induced negative moment; the recommended angle, at which the tendon applied,should be 25° ~ 45°; the minimum distance between the tendon should be 0. 5 m considering economy and the tensioning space rope,the distance between the tendon should not be too large,otherwise the uneven stress distribution of the slab could be caused; in the event that the calculated distance between tendon is too close or the calculated angle is too large,diameter of tendon should be adjusted to increase compressive stress of the slab and the reasonable distance and angle will be obtained.
引文
[1]黄晓明.水泥路面设计[M].北京:人民交通出版社,2003.
[2]张华.基于重载、重交通等特殊路段的水泥混凝土路面维修设计[J].公路工程,2011,36(1):84-87.
[3]Cesar Ivan Medina Chavez,B.Frank McCullough,David W.Fowler,Design of a Post-Tensioned Prestressed Concrete Pavement,Construction Guidelines,and Monitoring Plan,research report No.FHWA/TX-04/O-4035-1[Z].Center for Transportation Research,The University of Texas at Austin,Austin,TX,August 2003.
[4]黄卫,钱振东,牛赫东.预应力混凝土路面结构模型与数值分析(一)[J].西安公路交通大学学报,2000,20(3).11-15.
[5]陈博,刘德坤,王科.预应力混凝土T梁的预应力损失[J].公路工程,2012,37(3):241-250.
[6]蒋应军.重载交通水泥混凝土路面材料与结构研究[D].西安:长安大学,2005.
[7]李律,钱济,章李敦.基于ANSYS的预应力筋数值模拟[J].2007,32(4):178-183.
[8]ACI Committee 325,Recommendations for Designing Prestressed Concrete Pavement[J].ACI Structural Journal,Vol.85,No.4,July-Aug.1988,pp.451-471.
[9]李娜.斜向预应力混凝土路面研究[D].西安:长安大学,2011.
[10]李娜,张东省,徐希娟,等.斜向预应力混凝土路面设计方法研究[J].公路交通科技(应用技术版),2012(11):178-180.
[11]赵军卫,郑文忠.预应力混凝土局压承载力计算及端部间接钢筋的配置问题[J].工业建筑,2007(37):46-52.
[12]张东省,韩森,韩微微,等.斜张法双向预应力水泥混凝土路面关键设计参数研究[J].公路,2010(11):70-73.
[2]张华.基于重载、重交通等特殊路段的水泥混凝土路面维修设计[J].公路工程,2011,36(1):84-87.
[3]Cesar Ivan Medina Chavez,B.Frank McCullough,David W.Fowler,Design of a Post-Tensioned Prestressed Concrete Pavement,Construction Guidelines,and Monitoring Plan,research report No.FHWA/TX-04/O-4035-1[Z].Center for Transportation Research,The University of Texas at Austin,Austin,TX,August 2003.
[4]黄卫,钱振东,牛赫东.预应力混凝土路面结构模型与数值分析(一)[J].西安公路交通大学学报,2000,20(3).11-15.
[5]陈博,刘德坤,王科.预应力混凝土T梁的预应力损失[J].公路工程,2012,37(3):241-250.
[6]蒋应军.重载交通水泥混凝土路面材料与结构研究[D].西安:长安大学,2005.
[7]李律,钱济,章李敦.基于ANSYS的预应力筋数值模拟[J].2007,32(4):178-183.
[8]ACI Committee 325,Recommendations for Designing Prestressed Concrete Pavement[J].ACI Structural Journal,Vol.85,No.4,July-Aug.1988,pp.451-471.
[9]李娜.斜向预应力混凝土路面研究[D].西安:长安大学,2011.
[10]李娜,张东省,徐希娟,等.斜向预应力混凝土路面设计方法研究[J].公路交通科技(应用技术版),2012(11):178-180.
[11]赵军卫,郑文忠.预应力混凝土局压承载力计算及端部间接钢筋的配置问题[J].工业建筑,2007(37):46-52.
[12]张东省,韩森,韩微微,等.斜张法双向预应力水泥混凝土路面关键设计参数研究[J].公路,2010(11):70-73.