The bending st ress in the pavement of asphaltconcrete is recommended as cont rol objectives, asbending st ress in surface course is g reater than surfaceof base course. It is also found that the bending st ressin the surface of pavement increases wi th increasing ofdifferential sett lement of existing subgrade and the one to be w idened .The influences of Δi on bending stresses ofstructural courses in the pavement are illust rated inFig. 2 w ith the assumption of L =9. 0 m.Absolutestress v alues of courses of the pavement are l inear in-creased w ith increas ing of Δi ex c ept st res s in sub-basecourse.Fig. 2　I nfluence of Δi on bending stressof each pavement layerTens ile st ress in surface course and base of as-phalt pavement and compressive stress in sub-base arefound , and the critical Δi is 0. 36 %.4　ConclusionThe allow able maximum di f ferential sett lementis related to many parameters such as the module ofelastici ty , thickness of layers and relat ional coef ficientof the soil foundation .Therefore , some basic mea -sures about renovation in subgrade or in soil founda -tion could be taken to avoid damages of pavement ininterface zone of widened subgrade w hich due to dif-ferential set tlement , such as increasing stability of thebase before const ruction ,
leng thening the leng th ofdifferential sett lement or cont rolling differential set-tlement .According to the numerical calculation on an al-lowable differential sett lement of the highway ,0. 38 %is recommended as the threshold for an allow-able t ransverse g radient ratio of set tlement of thehighw ay . It is also regarded as a control standard fo rdifferential set tlement in pavement of w idened ex-pressw ay in order to ensure high speed , safety andcomfort of vehicles. In nearly two years , normal op-erat ion of the expres sw ay is also test i f ied the feasibil i-ty of Δi =0. 36 %reg arded as an al lowable transverseg radient ratio of set tlement in pavement , w hich is de -duced from this study .
摘要：标准路基的不均匀沉降是有用的保持在一个良好的服务条件。传统材料应力及其应用技术经济的理论用于分析路面结构的附加弯曲应力、等效弹性地基梁和影响路面结构的不均匀沉降。路面的容许沉降率指数(Δi)，用来评价路基的不均匀沉降标准的价值。路面容许沉降比例的指数应用于一个特定的高速公路项目，Δi<=0.36%达到了分析、计算和添加一定的安全系数。在过去的两年这个值是有效的被付诸实践。
毕业论文关键词：扩大和重建项目;不均匀沉降容许沉降率 标准路基拓宽工程英文文献和中文翻译(3):http://www.youerw.com/fanyi/lunwen_33189.html