算例9-2水泥混凝土路面设计（粒料基层）优化

粒料基层上混凝土面板厚度计算,,,,,,,,,,,,,,

(1)交通分析,,,,,,,,,,,,,,

方向分配系数=,,0.65,,,,,,,,,,,,

车道分配系数=,,0.36,,双向,0.5,,,,设计轴载Ps=,,100,KN,,

初期年平均日货车交通量（双向）=,,,,17517,,,,,最重轴载Pm=,,150,KN,,

设计车道年平均日货车交通量ADTT=,,,,5693,,,,,,,,,,

设计车道使用初期设计轴载日作用次数Ns=,,,,,164,次,,,,,,,,

设计基准期t（年）=,,,20,,,,,,,,,,,

基准期内货车交通量的年平均增长率gr=,,,,,5.0%,,,,,,,,,

设计基准期内设计车道所承受的设计轴载累计次数（轴次/车道）Ne=,,,,,,,7.126E+05,,,,,,,

（2）初拟路面结构,,,,,,,,,,,,,,

初拟普通混凝土面层厚度hc为,,,0.23,m,,,,,,,,,,

水泥稳定砂砾基层，hb厚为,,,0,m,,,,,,,,,,

底基层选用级配砾石，厚为,,,0.2,m,,,,,,,,,,

单向路幅宽度为,,,5.0+4.0m,,,,,,,,,,,

面层板平面尺寸为,,,L(m),,5,B(m),4,,,,,,,

,,,,,,,,,,,,,,,

(3)路面材料参数确定,,,,,,,,,,,,,,

面层弯拉强度标准值fr,,,4.5,Mpa,,,,,,,,,,

面层弯拉弹性模量Ec,,,29000,Mpa,,,水泥稳定砂砾基层弹性模量Eb,,,2000,Mpa,,,

面层泊松比Vc,,,0.15,,,,泊松比Vb,,,0.2,,,,

砾石粗集料混凝土的线膨胀系数αc=,,,,1.00E-05,/℃,,级配砾石底基层回弹模量,,,300,Mpa,,,

低液限粉土回弹模量为,,,,80,Mpa,,泊松比,,,0.35,,,,

湿度调整系数为,,,,0.8,,,,,,,,,,

路床顶综合回弹模量Eo为,,,,64,MPa,,,,,,,,,

粒料层当量回弹模量Ex=,,,,300,Mpa,,,,,,,,,

粒料层总厚度hx=,,,,0.2,m,,,,,,,,,

回归系数α=,,,,0.442,,,,,,,,,,

板底地基综合回弹模量Et=,,,,126.599,Mpa,,,,,,,,,

面层板弯曲刚度Dc=,,,,30.080,MNm,,,,,,,,,

半刚性基层板弯曲刚度Db=,,,,0.00,MNm,,,,,,,,,

路面结构总相对刚度半径rg=,,,,0.749,m,,,,,,,,,

（4）荷载应力,,,,,,,,,,,,,,

σps=,1.723,Mpa,,,,,,,,,,,,

σpm=,2.522,Mpa,,,,,,,,,,,,

应力折减系数Kr=,,0.87,,,,,,,,,,,,

综合系数Kc=,,1.05,,,,,,,,,,,,

疲劳应力系数Kf=,,2.156,,,,,,,,,,,,

σpr=,3.392,MPa,,,-2.775,3.713,,,,,,,,

"σp,max=",2.304,MPa,,,-0.483,21.356,0.045,0.955,,,,,,

,,,,,,,,,,,,,,,

（5）温度应力,,,,,,,,,,,,,,

最大温度梯度为,,88,℃/m,,,,,,,,,,,

Kn=,63043,Mpa/m,,rβ=,0.000,m,,ξ=,0.000,,,,,

t=,2.224,,,CL=,0.955,,,BL=,0.597,,-2.77541427,3.713476608,,

"σt,max=",1.753E+00,Mpa,,,,,,,,,-0.482596637,21.35621176,0.044940099,0.955

at=,0.841,,,bt=,1.323,,,ct=,0.058,,,,,

kt=,0.471,,,,,,,,,,,,,

σtr=,0.826,Mpa,,,,-0.607643952,,,,,,,,

（6）结构极限状态校核,,,,,,,,,,,,,,

γr=,1.06,,,误差%,,,,,,,,,,

γr(σpr+σtr）=,,,4.472,(0.629687169872785),,,,,,,,,,

"γr（σp,max+σt,max）=",,,4.300,(4.646067873573900),,,,,,,,,,

连续配筋混凝土面层纵向配筋计算,,,,,,,,,,,,,,

公路自然区划Ⅲ区新建一条一级公路，特重交通荷载等级，路基土为黏土，基层为水泥稳定碎石,,,,,,,,,,,,,,

面层厚hc=,,0.31,m,,,,,,,,,,,

基层厚,,0.18,m,,,,,,,,,,,

（1）计算参数,,,,,,,,,,,,,,

混凝土弯拉强度fr=,,5,Mpa,抗压强度fc=,,42,Mpa,抗拉强度ft=,,3.22,Mpa,,,

混凝土弹性模量Ec=,,31000,MPa,泊松比Vc=,,0.15,,重度γc=,,0.024,MN/m³,,,

混凝土的线膨胀系数αc=,,,1.10E-05,/℃,,面层与基层的摩阻系数μ=,,,7.5,,,,,

最大正温度梯度为,,,92,℃/m,,最大负温度梯度Tg=,,,30.7,,,,,

k1=,0.68,,年平均空气相对湿度ψa=,,,40%,,,,,,,,

钢筋埋置处混凝土温度与硬化时温度的最大温差ΔTξ=,,,,,,35,℃,,,,,,,

混凝土水灰比W/C=,,0.4,,混凝土用水量w0=,,1400,N/m3,a1=,1,,,,,

纵向钢筋选用HRB335,,,,,,,,,,,,,,

配筋率ρ=,,0.70%,,钢筋埋置深度ζ=,,0.1,m,钢筋直径ds=,,0.016,m,,,

钢筋线膨胀系数αs=,,,9.00E-06,/℃,,钢筋弹性模量Es=,,200000,Mpa,,屈服强度fsy=,,335,Mpa

（2）计算横向裂缝间距,,,,,,,,,,,,,,

=,0.0004845,,,0.0004534,,,8.384E-04,,,,,,,

,0.742,,,1.164E-04,,,,,,,,,,

,2.123,Mpa,,,,,,,,,,,,

混凝土板相对刚度半径r=,,,0.87,m,t=,1.48,,C=,0.494,,,,,

设平均裂缝初始值为,,,0.7,m,c1=,1.175,,,,,,,,

Ld=,0.76,m,（裂缝平均间距1.8m）,,,,,,,,,,,

（3）计算横向裂缝平均缝隙宽度,,,,,,,,,,,,,,

a=,0.84,b=,9.0360E+05,c=,(63.25),,2.03,,,,,,,

,0.48,mm（缝隙平均宽度0.5mm）,,,,,,,,,,,,

（4）计算裂缝