| 路面计算书 |
| |
项目名称：屈原至汨罗公路 |
|
|
|
项目概述及
路面结构说明 |
屈汨公路属平微二级公路，路面宽为9m，土路肩（一侧）宽1.5m；自然区划为Ⅴ3区，项目沿线砂砾石、水泥丰富，故推荐采用水泥砼路面结构，设计使用年限为30年。据交通量分析和轴载谱调查计算其设计使用年限内标准轴载累计作用次数为125085934次。路面结构面层采用24cm普通砼，基层采用15cm6%水泥稳定砂砾，底基层为15cm4%水泥稳定砂砾。面板尺寸为长5m，宽4.5m，纵缝为设拉杆平缝，横缝为设传力杆缩缝。本结构适用于路基干燥中湿路段。 |
| 一 |
计算路基基顶当量回弹模量及砼面层相对刚度半径输入数据 |
| 1 |
普通砼面层弯拉弹性模量Ec（MPa） |
= |
31000 |
|
|
|
| 2 |
面层厚度h（m） |
= |
0.24 |
|
|
|
| |
|
|
|
|
|
|
| 3 |
基层材料回弹模量E1（MPa） |
= |
1500 |
|
|
|
| 4 |
基层厚度h1（m） |
= |
0.15 |
|
|
|
| |
|
|
|
|
|
|
| 5 |
底基层材料回弹模量E2（MPa） |
= |
1300 |
|
|
|
| 6 |
底基层厚度h2（m） |
= |
0.15 |
|
|
|
| |
|
|
|
|
|
|
| 7 |
土基回弹模量E0（MPa） |
= |
50 |
|
|
|
| |
|
|
|
|
|
|
| 二 |
计算荷载疲劳应力输入数据 |
| 1 |
接缝传荷能力的应力折减系数kr |
= |
0.87 |
|
|
|
| 2 |
综合系数kc |
= |
1.2 |
|
|
|
| 3 |
设计基准期内标准轴载累计作用次数Ne(次） |
= |
125085934 |
|
|
|
| 4 |
计算荷载疲劳应力系数v |
= |
0.057 |
|
|
|
| |
|
|
|
|
|
|
| 三 |
计算温度疲劳应力输入数据 |
| 1 |
温度梯度值Tg（°C/m） |
= |
87 |
|
|
|
| 2 |
板长L（m） |
= |
5 |
L/r |
= |
7.75 |
| 3 |
由图B.2.2根据砼面板厚h及L/r查得温度应力系数Bx |
= |
0.64 |
|
|
|
| 4 |
面层砼弯拉强度标准值fr（MPa） |
= |
5 |
|
|
|
| 5 |
回归系数a |
= |
0.841 |
|
|
|
| 6 |
回归系数b |
= |
0.058 |
|
|
|
| 7 |
回归系数c |
= |
1.323 |
|
|
|
| |
|
|
|
|
|
|
| 四 |
计算极限状态输入数据 |
| 1 |
可靠度系数Rr |
= |
1.13 |
|
|
|
| |
|
|
|
|
|
|
| 一 |
新建公路的基顶当量回弹模量及面层相对刚度半径计算 |
| |
Ex |
= |
(h12*E1+h22*E2)/(h12+h12) |
|
|
|
| |
|
= |
1400.00 |
|
|
|
| |
|
|
|
|
|
|
| |
Dx |
= |
(E1*h13+E2*h23)/12+((h1+h1)2/4)*(1/(E1*h1)+1/(E2*h2))-1 |
|
|
| |
|
= |
3.14 |
|
|
|
| |
|
|
|
|
|
|
| |
hx |
= |
(12*Dx/Ex)^(1/3) |
|
|
|
| |
|
= |
0.30 |
|
|
|
| |
|
|
|
|
|
|
| |
a |
= |
6.22*(1-1.51*(Ex/E0）-0.45） |
|
|
|
| |
|
= |
4.12 |
|
|
|
| |
|
|
|
|
|
|
| |
b |
= |
1-1.44*(Ex/E0）-0.45 |
|
|
|
| |
|
= |
0.77 |
|
|
|
| |
|
|
|
|
|
|
| |
基层顶面当面回弹模量Et |
= |
a*hxb*E0*(Ex/E0)1/3 |
|
|
|
| |
|
= |
247.60 |
|
|
|
| |
|
|
|
|
|
|
| |
普通砼面层的相对刚度半径r |
= |
0.537*h*(Ec/Et)(1/3) |
|
|
|
| |
|
= |
0.645 |
|
|
|
| |
|
|
|
|
|
|
| 二 |
荷载疲劳应力计算 |
| |
荷载应力σps |
= |
0.077*r0.6*h-2 |
|
|
|
| |
|
= |
1.03 |
|
|
|
| |
|
|
|
|
|
|
| |
疲劳应力系数kf |
= |
Nev |
|
|
|
| |
|
= |
2.894 |
|
|
|
| |
|
|
|
|
|
|
| |
荷载疲劳应力σpr |
= |
kr*kf*kc*σps |
|
|
|
| |
|
= |
3.10 |
|
|
|
| |
|
|
|
|
|
|
| 三 |
温度疲劳应力计算 |
| |
温度翘曲应力σtm |
= |
αc*Ec*h*Tg*Bx/2 |
|
|
|
| |
|
= |
2.07 |
|
|
|
| |
|
|
|
|
|
|
| |
温度疲劳应力系数kt |
= |
(fr/σtm)*(a*(σtm/fr)c-b) |
|
|
|
| |
|
= |
0.493 |
|
|
|
| |
|
|
|
|
|
|
| |
温度疲劳应力σtr |
= |
kt*σtm |
|
|
|
| |
|
= |
1.02 |
|
|
|
| |
|
|
|
|
|
|
| 四 |
极限状态计算 |
| |
Rr*（σpr+σtr） |
= |
4.66 |
|
|
|
| 结论 |
综合疲劳应力小于面层砼弯拉标准强度值，能够满足使用要求 |
