【正文】 1500二灰土待定550土基—38——：H（m）材料名稱20℃抗壓模量（MPa）4cm細(xì)粒式瀝青混凝土14008cm中粒式瀝青混凝土120025cm密級(jí)配瀝青碎石1500待定二灰土600土基38確定石灰土的厚度（換算成三層體系）：令理論彎沉值等于設(shè)計(jì)彎沉值：，其中： 令LR= ∴查規(guī)范得 ∴查規(guī)范得∴查表得： ∴根據(jù)∴ 取彎拉應(yīng)力的驗(yàn)算：瀝青混凝土頂層 = , , 查圖三層連續(xù)體系上層拉應(yīng)力系數(shù)諾謨圖得為壓應(yīng)力，不需驗(yàn)算。計(jì)算二灰土底基層容許彎拉應(yīng)力：，∴故該路面結(jié)構(gòu)符合要求。： 式中 ：——100KN的單軸—雙輪組標(biāo)準(zhǔn)軸載的作用次數(shù)； —單軸—單輪、單軸—雙輪組、雙軸—雙輪組或三軸—雙輪組軸型i級(jí)軸載的總重KN； —各類軸型i級(jí)軸載的作用次數(shù)； —軸型和軸載級(jí)位數(shù)； —軸—輪型系數(shù)，單軸—雙輪組時(shí)，=1；單軸—單輪時(shí)，按式計(jì)算；雙軸—雙輪組時(shí)，按式；三軸—雙輪組時(shí)，按式計(jì)算。： 根據(jù)表設(shè)計(jì)規(guī)范，高速公路的設(shè)計(jì)基準(zhǔn)期為30年，安全等級(jí)為一級(jí)，~，則：其交通量在中，故屬重型交通。橫縫為設(shè)傳力桿的假縫，縱縫施工縫采用拉桿平縫形式。路基回彈模量取30MPa，石灰粉煤灰穩(wěn)定土墊層回彈模量取600MPa，水泥穩(wěn)定粒料基層回彈模量取1300MPa?？紤]到設(shè)計(jì)基準(zhǔn)期內(nèi)荷載應(yīng)力累計(jì)疲勞作用的疲勞應(yīng)力系數(shù)。荷載疲勞應(yīng)力計(jì)算為：溫度疲勞應(yīng)力計(jì)算： 查規(guī)范可知，IV6區(qū)最大溫度梯度取92℃。最大溫度梯度時(shí)混凝土板的溫度翹曲應(yīng)力計(jì)算為：回歸系數(shù)查規(guī)范可知，自然規(guī)劃IV6區(qū)a= b= c=溫度疲勞應(yīng)力系數(shù)溫度疲勞應(yīng)力計(jì)算： 查規(guī)范可知，高速公路的安全等級(jí)為一級(jí)，相應(yīng)于一級(jí)安全等級(jí)的變異水平等級(jí)為低級(jí)，目標(biāo)可靠度為95%。 方案二：，底基層選用水泥穩(wěn)定粒料（水泥用量5%）。碾壓混凝土不設(shè)縱縫，橫縫為假縫，間距4m。此時(shí)。水泥混凝土面層,考慮設(shè)計(jì)基準(zhǔn)期內(nèi)荷載應(yīng)力累計(jì)疲勞作用的疲勞應(yīng)力系數(shù)。普通混凝土面層的荷載疲勞應(yīng)力計(jì)算：碾壓混凝土基層的荷載疲勞應(yīng)力計(jì)算： 溫度疲勞應(yīng)力計(jì)算：IV6區(qū)最大溫度梯度?。?2℃/m）。最大溫度梯度時(shí)普通混凝土上面層的溫度翹曲應(yīng)力計(jì)算：回歸系數(shù)查規(guī)范可知，自然規(guī)劃IV6區(qū)a= b= c=普通混凝土面層的溫度疲勞應(yīng)力系數(shù)計(jì)算溫度疲勞應(yīng)力：分離式復(fù)合式路面中碾壓混凝土基層的溫度翹曲應(yīng)力可忽略不計(jì)。確定可靠度系數(shù)普通混凝土面層碾壓混凝土基層，可以承受設(shè)計(jì)基準(zhǔn)期內(nèi)荷載應(yīng)力和溫度應(yīng)力的綜合疲勞作用。橫縫為設(shè)傳力桿的假縫，縱縫施工縫采用拉桿平縫形式。路基回彈模量取30MPa，石灰粉煤灰穩(wěn)定土墊層回彈模量取600MPa，水泥穩(wěn)定粒料基層回彈模量取1300MPa?？紤]到設(shè)計(jì)基準(zhǔn)期內(nèi)荷載應(yīng)力累計(jì)疲勞作用的疲勞應(yīng)力系數(shù)。 荷載疲勞應(yīng)力計(jì)算為：溫度疲勞應(yīng)力計(jì)算： 查規(guī)范可知，IV6區(qū)最大溫度梯度取92℃。最大溫度梯度時(shí)混凝土板的溫度翹曲應(yīng)力計(jì)算為：回歸系數(shù)查規(guī)范可知，自然規(guī)劃IV6區(qū)a= b= c=溫度疲勞應(yīng)力系數(shù)溫度疲勞應(yīng)力計(jì)算： 查規(guī)范可知，高速公路的安全等級(jí)為一級(jí)，相應(yīng)于一級(jí)安全等級(jí)的變異水平等級(jí)為低級(jí)，目標(biāo)可靠度為95%。對(duì)水泥砼路面和瀝青砼路面兩種方案比較如下表：比較項(xiàng)目瀝青路面水泥砼路面使用壽命設(shè)計(jì)年限15年，可通過維修延長(zhǎng)使用年限設(shè)計(jì)年限30年造 價(jià)低稍高平坦性及震動(dòng)噪音行車舒適、噪音和震動(dòng)小產(chǎn)生接縫震動(dòng)、噪音稍大明色性路面反光能力弱，視覺柔和路白光較強(qiáng)，視覺效果差施工性受環(huán)境因素影響小，施工進(jìn)度快受外界影響大，養(yǎng)生期長(zhǎng)，工期長(zhǎng)抗變形能力及耐磨性材料選擇不當(dāng)時(shí)易產(chǎn)生車轍，耐磨性差，寒地易出現(xiàn)裂縫難以產(chǎn)生車轍變形，耐磨性強(qiáng)，基層壓實(shí)度不均勻時(shí)易產(chǎn)生裂縫維修難易養(yǎng)護(hù)維修工藝簡(jiǎn)單維修規(guī)模大，復(fù)雜地下管線維修及增設(shè)便于地下管線維修與增設(shè)不便于管線維修、增設(shè)，路面不易恢復(fù)，費(fèi)用高水泥混凝土路面的特點(diǎn)：它是一種剛度大；擴(kuò)散荷載應(yīng)力的能力強(qiáng)；穩(wěn)定性好和使用壽命長(zhǎng)的路面結(jié)構(gòu)，和其他路面結(jié)構(gòu)相比有以下優(yōu)點(diǎn)：強(qiáng)度高，穩(wěn)定性好，受水的漫入和氣候溫度等自然因素影響時(shí)，引起的強(qiáng)度變化小，耐久性好，養(yǎng)護(hù)維修費(fèi)用小，抗滑性能好，有利于夜間行車等。路面結(jié)構(gòu)直接曝露在大氣之中，瀝青路面的動(dòng)彈模量隨溫度的升高變化大，路基回彈模量隨濕度的增長(zhǎng)而急劇下降。路面結(jié)構(gòu)面層采用瀝青混凝土15cm、基層采用水泥碎石25cm、底基層采用石灰土15cm。s critical infrastructure, the roads to the development of production, economic prosperity and international exchanges, facilitate people39。s democratic revolution, the great forerunner Dr. Sun Yatsen once said : The roads were also the mother of civilization. Pulse also wealth, the concept trial today civilized nations that most country roads. Thus, highway on the national economy. people39。Key Words: bridges and Highway building roads After the reform and opening up, with the national economy. Stability. Highspeed development, road construction boom upward, is in an unprecedented upsurge in the building. Taking a panoramic view of China39。s road constructions are facing severe challenges. In the national economy continued its rapid growth and urbanization process will continue to accelerate the process, various cities facing redevelopment, transformation, expansion and replanning, and road infrastructure building is the present and future urban development. Highway understanding of the history and development of the status quo, for how we sustained development of the national economy based on the strategic goals the development and planning of the new era of highway construction in the sustainable development strategy is very important. 1. A modern highway39。s modern highway development has undergone the following two stages ： the reform and opening up of road infrastructure building The old China39。s the later period, is the adaption economy develops and develops the border area the need, our country starts the largescale construction to lead to the border area and the mountainous area road, has constructed the ChengduLhasa Highway, the QinghaiTibet Highway one after another, and in the southeast coast, northeast and southwest the local construction national defense highway, the road course rapid growth, in 1959 amounted to more than500,000 kilometers.The 6039。s intermediate stages our country starts to the QinghaiTibet Highway to carry on the technological transformations, the 8039。s endachieved 890,000 kilometers, the average increased approximately30,000 kilometers every year, the road density achieved 9. 3 kilometers hundred square kilometers. After the reform and opening up road infrastructure building and achievements. After the reform and opening up, the national economy continued its rapid development, road transport demand is robust growth, Highway infrastructure construction began a historic changes, and its main features : Highway construction of the central and local levels, the attention of the government, If you want to get rich, the first road, Highway construction of the importance of gradually recognized by the whole society. In the basis of unified planning, started a program of the National Highway infrastructure construction, the early 1980s and late 1980s, national trunk highway network and the National Road Route Planning System has drawn up and implemented, Highway building with a clear overall goals and milestones. Highway construction continued to expand the overall size, while focusing on the strengthening of quality improvement, Expressway and other highgrade highways to develop rapidly. The country39。s highways has made outstanding achievements. In 1988, China39。s highway construction experiencing a basic adaptation of national economic developmentnot suited to the development of the national economyconstraining the development of the national economy constraints on the national economy marked improvement process. Economic development, transportation first, its validity for the whole society has been proven by the practices. Therefore, pletely changed our transport and the backward state of the passive situation, is the progressive realization of the modernization of China39