【作者】 韩冬；

【导师】 张维全；

【作者基本信息】 重庆交通大学 ， 道路与铁道工程， 2011， 硕士

【摘要】 县乡公路连接着国道、省道、干线公路,是沟通城乡物资、经济、技术及文化交流的桥梁和纽带。建设高质量的县乡公路对推动农村经济发展,实现广大人民群众脱贫致富奔小康具有重要的意义。而支挡结构在很大程度上影响着公路的长期稳定及工程造价,传统的重力式挡土墙或衡重式挡土墙由于其圬工量大、造价高、占地多、施工不便等诸多弊病已无法适应县乡公路建设的需要。因此,为县乡公路提供一种造价低廉、适用性强、施工简便的支挡结构形式势在必行。针对这一问题,综合现有支挡结构形式,本文选用了两种具有较大技术经济优势的支挡结构—加筋土挡土墙和加筋格宾挡土墙,并为了使其更好适应低等级公路建设,对其结构进行了优化设计,并进行了受力变形等方面的研究。本文以云南普洱市小碧公路路肩式加筋土支挡结构形式为依据,通过运用ANSYS软件对加筋土挡土墙和加筋格宾挡墙的破裂面产生发展过程、变形特性、不同填土性质对支挡结构变形的作用规律进行了模拟分析和计算,并结合岩土工程软件Plaxis的计算结果对其进行了验证。并通过近年来国内外加筋土工程实例对两种加筋土支挡结构进行了深入地技术经济评价,主要研究成果如下:1、两种加筋土支挡结构的破裂面均不同于传统的0.3H型和朗金-库伦简化破裂面,加筋土挡土墙的破裂面产生于挡墙底部,并在加筋体内呈对数螺旋线式向上发展,而加筋格宾挡墙的破裂面则发生发展于加筋体外的筋带末端附近,说明相比于加筋土挡墙,加筋格宾应加强外部稳定验算;2、通过有限元强度折减计算,发现加筋土挡墙和加筋格宾挡墙的水平位移分布均与传统土压力作用模式有较大差别,墙体中下部土压力较大,呈“两头下,中间大”的分布趋势,同时,加筋对降低土体沉降作用并不理想,需在实际工程中做好预防措施;3、较大的填土弹性模量、粘聚力及内摩擦角对加筋土结构起稳定作用,但相比于弹性模量、粘聚力,填土内摩擦角对挡墙变形的影响作用更大,在今后的加筋土工程中,为达到既稳定又经济的目标,应主要考察作为填料土体的内摩擦角,适当满足粘聚力和弹性模量要求;4、相比于低等级公路中常用的重力式挡土前和衡重式挡土墙,加筋土挡土墙和加筋格宾具有压倒性的技术经济优势,其力学性能更好,施工简便、速度快,对施工人员的技术要求低,质量易于控制,生态环保,造价低廉。同时,在保证稳定的前提下,通过对布筋方式的优化,使加筋土支挡结构较之以往更具稳定性和经济性,节省筋带用量,从而节约工程投资。更多还原

【Abstract】 As the connection of national highways , provincial highways and trunk highways , the county level highways have linked the rural and urban in means of material exchange , economic exchange , technical exchange and cultural exchange , etc . Tt is of great significance in proving the development of rural economic and achieving the goal of shaking off poverty and seting out on a road to prosperity that how to build a high quality county level highways . The retaining structures largely affected the long-term stabilization and construction cost of the highways . The conventional gravity retaining wall may not meet the requirements of the county level highways for the sake of its features of large masonry , high cost , wasteful of land , construction complex and so on . Therefore , it is required by circumstances that providing a new type of retaining structure with the advantages of low cost , fine applicability , easy maitenance . To address the issue and combine the existing retaining walls , reinfored earth retaining wall and reinforced gabion , which has a advantages of economic and technical , has been chosen for study . The optimization design and stress-deformation study of the two kinds of walls has done so that they can adapt the construction of the county level highways much better.This text is based on the shoulder reinforced retaining wall in Pu’er City of Yunnan Province . ANSYS software has been applied to anlyze the reinforced earth retaining wall and reinforced gabion wall , then the anlysis results has been inspected and verified by the calculation of PLAXIS . It has been studied and anlyzed that the two kinds retaining walls’development of fracture plane , deformation characteristics , deformation rule of different filler properties with the use of finite element method . Also the technical and economic evaluation has been anlyzed by the comparison of home and abroad exemples in recent years . The main results can be concluded as follows : 1 The fracture planes of both the reinforced earth retaining wall and reinforced gabion wall are different from traditional“0.3H”and“Rinkine-Kulun”simplified fracture planes . The fracture plane of reinforced earth retaining wall produced at the foot of the wall , and developed upwards asumming a log-spiral posture in the reinforced body ; however , the fracture plane’s development and progression of reinforced gabion wall is on the outside of the reinforced body along the ends of the ribs , which explains that the reinforced gabion wall should strengthen the exterior strain-stress calculation compared to the reinforced earth retaining wall .2 It can be revealed by the strength reduction of finite element calculation that the distribution of horizontal deformation of both the two kinds retaining walls are different from the tradional earth pressure binding mode . The larger earth pressure of the walls produced at the lower of the middle part , assuming a case of both the ends being small and the middle being large . And the reinforced measure has a low retarding effect on the subsidence of the structure . 3 The bigger elasticity modulus , cohesive srength , internal frictional angel of the filler can make the structure more steady . Contrast to the elasticity modulus and cohesive strength , the internal fricrional angel of the filler contributes more to the horizontal deformation of walls . So in the future reinforced construction , the internal frictional angle is the primary considering indicator compared with the elastivity modulus and cohesive strength in order to the goal of both steady and economical . 4 Compared to the conventional gravity retaining wall , the reinforced earth retaining wall and reinforced gabion wall overwhelming superiority in technical and economic aspect , which has a better mechanical property , construction easier and faster , lower technique request of the builder , easier to control construction quality , better ecological environmental protected and lower cost features . Besides , on the premise of the stability , the arrangement ways of reinforcement has been optimum designed , so that the walls are more steady and economical than ever , and the dosage of the reinforced ribs has been cut back , which attains the goal of saving costs .更多还原