【摘要】：基于有限元軟件KENSLABS,構(gòu)建了水泥混凝土路面輪載損傷計(jì)算模型,引入地基季節(jié)調(diào)整系數(shù)與零養(yǎng)護(hù)疲勞準(zhǔn)則,分析了土基模量整體削弱對(duì)路面疲勞開(kāi)裂指數(shù)的影響,探討了當(dāng)量軸載系數(shù)與多軸通過(guò)一次的計(jì)算次數(shù)對(duì)土基模量的依賴性,研究了不同土基模量下板厚、水泥混凝土抗彎拉強(qiáng)度、單軸軸重、單軸每日重復(fù)作用次數(shù)等核心路面設(shè)計(jì)參數(shù)與路面開(kāi)裂指數(shù)的關(guān)系。研究結(jié)果表明:水泥混凝土路面疲勞開(kāi)裂指數(shù)隨著地基季節(jié)調(diào)整系數(shù)的減小而增大,增大速度隨地基季節(jié)調(diào)整系數(shù)的減小而加快,當(dāng)?shù)鼗竟?jié)調(diào)整系數(shù)從1.0減小為0.8和從0.4減小為0.2時(shí),在單軸、雙軸和三軸荷載作用下,路面開(kāi)裂指數(shù)分別增大了2.8、2.9、1.5倍和49.8、269.0、1 351.4倍;當(dāng)量軸載系數(shù)與多軸通過(guò)一次的重復(fù)計(jì)算次數(shù)受到板厚與土基模量的影響,在土基模量為60 MPa,板厚為15cm或35cm時(shí),單軸荷載比雙軸荷載更易產(chǎn)生損傷,雙軸荷載比三軸荷載更易產(chǎn)生損傷,在土基模量為20MPa,板厚為15cm時(shí)也是如此,但在土基模量為20MPa,板厚為35cm時(shí),結(jié)論則與前相反;水泥混凝土路面疲勞開(kāi)裂指數(shù)隨著面板厚度、水泥混凝土抗彎拉強(qiáng)度、單軸軸重、單軸每日重復(fù)作用次數(shù)而改變的幅度與土基模量直接相關(guān),當(dāng)土基模量為20、60 MPa時(shí),面板厚度從21cm增加到25cm,疲勞開(kāi)裂指數(shù)分別減小1.18×10、1.18×10~(-2),當(dāng)混凝土抗彎拉強(qiáng)度從4.0 MPa增大到4.4 MPa,疲勞開(kāi)裂指數(shù)分別減小1.28、2.20×10~(-3),當(dāng)單軸軸重從80kN增大到160kN時(shí),疲勞開(kāi)裂指數(shù)分別增大5.48、7.36×10~(-3),當(dāng)單軸荷載每日重復(fù)作用次數(shù)從50增加到90時(shí),疲勞開(kāi)裂指數(shù)分別增大2.05×10-1、5.07×10~(-4);增設(shè)厚度為15cm的水泥穩(wěn)定基層后,設(shè)定工況下的路面疲勞開(kāi)裂設(shè)計(jì)壽命增加3.42年;在提高土基模量的同時(shí),宜優(yōu)先考慮適當(dāng)增加板厚,嚴(yán)禁超載,設(shè)置水泥穩(wěn)定基層等措施,可以控制水泥混凝土路面受輪載作用的疲勞開(kāi)裂破壞。
[Abstract]:Based on the finite element software KENSLABS, the calculation model of wheel load damage of cement concrete pavement is constructed. The seasonal adjustment coefficient of foundation and zero maintenance fatigue criterion are introduced, and the influence of the overall weakening of soil foundation modulus on the fatigue cracking index of pavement is analyzed. The dependence of equivalent axial load coefficient and multi-axial calculation times on soil foundation modulus is discussed. The slab thickness, bending tensile strength and uniaxial load of cement concrete under different soil foundation modulus are studied. The relationship between core pavement design parameters such as uniaxial daily repetition times and pavement cracking index. The results show that the fatigue cracking index of cement concrete pavement increases with the decrease of seasonal adjustment coefficient of foundation, and the increasing speed increases with the decrease of seasonal adjustment coefficient of foundation. When the seasonal adjustment coefficient of foundation decreases from 1.0 to 0.8 and from 0.4 to 0.2, the pavement cracking index increases by 2.8, 2.9, 1.5 times and 49.8269.0, respectively, under uniaxial, biaxial and triaxial loads. The repeated calculation times of equivalent axial load coefficient and multiaxial pass are affected by plate thickness and soil foundation modulus. When the soil foundation modulus is 60 MPa, plate thickness is 15cm or 35cm, uniaxial load is more likely to cause damage than biaxial load. Biaxial load is more likely to cause damage than triaxial load, the same is true when the modulus of soil foundation is 20 MPA and the thickness of plate is 15cm, but when the modulus of soil foundation is 20 MPA and the thickness of plate is 35cm, the conclusion is opposite to that of the former. The fatigue cracking index of cement concrete pavement is directly related to the modulus of soil foundation when the modulus of soil foundation is 20 and 60 MPa, with the variation of fatigue cracking index of cement concrete pavement with the thickness of face slab, the bending tensile strength of cement concrete, the uniaxial load and the number of daily repeats of uniaxial. When the thickness of panel increases from 21cm to 25 cm, the fatigue cracking index decreases by 1.18 脳 10 ~ (- 2) and 1.18 脳 10 ~ (- 2), respectively, and when the bending tensile strength of concrete increases from 4.0 MPa to 4.4 MPa, the fatigue cracking index decreases by 1.28,2.20 脳 10 ~ (- 3), respectively. When the uniaxial load increases from 80kN to 160kN, the fatigue cracking index increases by 5.48,7.36 脳 10 ~ (- 3), and when the daily repetition number of uniaxial load increases from 50 to 90, the fatigue cracking index increases by 2.05 脳 10 鈮，

本文編號(hào)：2480740