某二级公路路面设计实例(3)

a?f(h?,E2E)?f(0.282,0.714)?7.681 L2p?d?1000由

EacF1

ac?ak1k2得

k2?0.511

查三层体系表面弯沉系数诺谟图得

H??5.22 H?55.5 9n?1由H??hE4K2.4K?2E?h?hE2?h34?h52.45E=55.5922

得：h5?32.65cm取h5?35cm

7层底拉应力验算

采取15°C时的抗压模量，细粒式密级配沥青混凝土为2000MPa，中粒式密级配沥青混凝土为1800MPa，粗粒式密级配沥青混凝土为1400MPa。

1. 对于细粒式沥青混凝土层

H?4E?hE3?hE4E2?h30.940.9+h50.95=36.0 K?n?1hk0.9E?i?1i?1E2E2E2H??36.0010.65=3.381

h??310.65=0.282

E0E?301800?0.0172

E2E?18002000?0.91

查三层连续体系上层底面弯拉应力系数诺谟图（上层中层层间连续）

??f(,2)?E1=f(0.282,0.9)≤0

hE

??P?m1m2≤0 ???R

查三层连续体系中层底面弯拉应力系数诺谟图（上层中层层间连续）

h＝h1＝3cm H＝？

E1＝2000MPa E2＝1800MPa E0＝30MPa

n1=f(E2H,)?f(0.9,3.381)?1.234E1?n2HhE=f(,,2)?f(3.381,0.282,0.9)=0.31??E1

??f(H,E0)?f(3.381,0.017)=0.341

?E2??P?n1n2=0.7×0.341×1.234×0.31=0.091≤0.636

2. 对于中粒式沥青混凝土层

h1??hk4k?1iE1800Ekh141?h2?34?5?8.19E1400Ei= 2

H?

K?i?1?n?1hk0.9EkEEE1500550?h30.93?h40.94?h50.95?7?200.9?350.9=40.99Ei?1E3E3E314001400H?h?3.8 5?0.769?h＝? H＝？

E1＝1800MPa E2＝1400MPa E0＝30MPa

E030??0.02E21400

E21400??0.778E11800

查三层连续体系上层底面弯拉应力系数诺谟图（上层中层层间连续）

??f(,2)?E1=f(0.769,0.778)≤0

hE

??P?m1m2≤0

???R

查三层连续体系中层底面弯拉应力系数诺谟图（上层中层层间连续）

n1=f(E2H,)?f(0.778,3.85)?1.166E1?n2=f(HhE2,,)?f(3.85,0.769,0.778)=0.25 ??E1HE0,)?f(3.85,0.02)=0.26?E2??f(

??P?n1n2?0.053?0.455

3. 对于粗粒式沥青混凝土层

h??hk4K?1iEkEE20001800?h141?h242?h3?3?4?6?4?7?16.67EiE3E314001400EkE550?h4?h50.95?20?350.9=31.48 Ei?1E41500 h＝? H＝？

H?HK?i?1?n?1hk0.9?h?2.96?1.57

E1＝1400MPa E2＝1500MPa E0＝30MPa

?E030??0.02E21500E21500??1.07E11400

查三层连续体系上层底面弯拉应力系数诺谟图（上层中层层间连续）

??f(,2)=f(1.57,1.07)?0

?E1hE??P?m1m2≤0

???R

查三层连续体系中层底面弯拉应力系数诺谟图（上层中层层间连续）

n1?f(E2H,)?f(1.07,2.96)?1.23=1.23E1?

n2=n2?f(

HhE2,,)?f(2.96,1.57,1.07)?0.46??E1??f(HE0,)?f(2.96,0.02)?0.46 ?E2??P?n1n2=0.182≤0.331

4. 对二灰碎石

h??hk4K?1iEkEEE?h141?h242?h343?h4EiE4E4E4

?3?4H?H200018001400?6?4?7?4?20?36.38150015001500hk0.9Ek?35 Ei?1k?i?1?n?1?h?3.29

?3.42

?E030??0.05E2550

E21500??2.73E1550

查三层连续体系上层底面弯拉应力系数诺谟图（上层中层层间连续）

h＝? H＝？

E1＝1500MPa

E2＝550MPa

E0＝30MPa

??f(,2)?E1=f(3.42,2.73)≤0

hE??P?m1m2≤0

???R

查三层连续体系中层底面弯拉应力系数诺谟图（上层中层层间连续）

n1=n1?f(E2H,)?f(2.73,3.29)?1.31E1?

n2=n2?f(

HhE2,,)?f(3.29,3.42,2.73)?0.53??E1??f(HE0,)?f(3.29,0.05)?0.25 ?E2??P?n1n2=0.174≤0.303

综上所述，各层均满足要求。