【作者】 张飞；

【导师】 池秀文； 陈静曦；

【作者基本信息】 武汉理工大学 ， 采矿工程， 2005， 硕士

【摘要】 生态防护技术是随着世界范围内高速公路建设而兴起的一门工程技术。与传统的工程防护技术不同,生态防护技术充分利用植物自身特点并结合必要的工程防护起到工程建设与环境保护兼顾的目的。在越来越重视环境保护和生活质量的今天,生态防护已成了公路边坡防护的一种趋势,代表着边坡防护的发展方向。 高速公路边坡生态工程在我国目前没有成功的经验和定型的模式,更无技术规范可循。目前生态防护技术研究主要集中在对施工工艺以及水土保持学的研究,忽略了坡面植物根系的工程力学行为及与植物防护与工程防护相结合防护的研究,导致防护理论远远落后于防护技术应用的发展,制约生态防护技术在边坡工程中的应用。本文基于湖北省交通厅科技项目(孝(感)—襄(樊)高速公路边坡防护和生态恢复技术研究与应用课题),在对现有生态防护理论及应用的相关资料研究的基础上,采用多种研究方法和理论,系统的研究了边坡生态防护的力学效应。评价了工程防护和生态防护方式的经济效益;从微观的角度研究根系——土壤复合体的宏观力学性质;通过现场试验,研究了根系的力学性质、根系——土壤复合体和土壤的抗剪强度以及两者的抗水蚀能力;通过计算机模拟试验,研究了土壤和根系——土壤复合体的应变。结果表明,生态防护对加固土壤、保护边坡体有可支持的力学依据,能够有效的提高土壤的力学性质。 在理论研究中,采用复合材料理论的研究方法,通过细观力学等效模型来分析描述根系土的宏观力学性能,以及其细观结构与宏观性能之间的关系。分析表明,复合体的力学性质与各组分(即土壤、根系)力学性质以及各组分的体积分数存在一定关系。一般情况下,复合体的各力学常数与各组分的力学性质或根系的体积分数正相关。 在现场试验中,通过对土和根系土的抗剪强度、根系的抗拉强度、根系土的抗水蚀能力几个方面的试验研究,分析根系对土壤的强度加固作用。抗剪强度研究表明,根系的加入减小了复合体的最小主应力,使复合体的的抗剪强度增强;抗水蚀试验表明根系对土的加固作用,减少了土的流失。 在虚拟试验中,通过有限元模拟土壤、根系——土壤复合体的单轴压缩试验,分析两种土壤在相同应力状态下的不同应变,比较他们的弹性模量,进一步分析根系的加固作用。试验结果表明,在相同应力状态下,根系——土壤复合体的应变比土壤小;通过反算各弹性模量,复合体的弹性模量高于土壤的,尤其在根系长度方向作用比较明显。更多还原

【Abstract】 Eco-Protection Technology is a kind of engineering technology rising with construction of Expressway in the whole world. Different from the traditional engineering protection technology, Eco-Protection Technology utilize plant its own characteristic and combine essential engineering protection to achieve the purpose of consideration between engineering construction and environmental protection fully, People pay attention to environmental protection and life quality more and more nowadays, Using Eco-Protection Technology becomes a kind of trend in slope protection of highway, it also represent the developing direction of slope protection.There have no successful experience and no final model of design about slope protection of highway at present in our country, and have no technical regulations to follow even more. At present research of Eco-Protection Technology concentrate on construction craft and research on water and soil conservation mainly, neglect domatic plant engineering mechanics behavior of root system protection researchs combined together with plant protection and engineering protection, it result in the protect theory far its lag behind development of the protecting technical application, restrain the application of Eco-Protection Technology in slope protection. This paper, based on the study results of the Scientific and Technological Project of Hubei Provincial Communications Department (The Subject on Study and Application the Technology of Slope Protection and Ecological Restoration along the expressway from Xiaogan City to Xiangfan City Hubei Province) , on the basis of study the available relevant materials about the Eco-Protection theory and application, it summarizes the mechanical action of Eco-protection by numberial theories and ways. Appraised the economical benefits of the Eco-protection and Engineering protection, studied the mechanical property of the root/soil composite in Micro-theory, and the hydraulic action by water-rushing tests, also the strain by computer simulation. All results indicate there have reasonable mechanical theory for supporting the Eco-protection technology which can improve the mechanical property of soil.In the theoretic studies, on the basis of the composite material theory ,we study the Macro-mechanical property by building Micro-mechanical model. Results show the more high the mechanical property or the percent composition of root, the more strong the root/soil composite will be.In the tests, on the basis of the shear test of soil and composite, the tensile test ofroot and the water-rushing test, we analyzed the reinforcing ability of root. From the shear test, we found the shear strength of the composite, because of reducing the minimum normal stress by roots, has been greatly improved; from the water-rushing test, we also found the root can keep the soil.In the computer simulation test, on the basis of the finite element method which been used to simulate the single-axial compression test of soil and composite, we analyzed their strains and elastic modulus. From the test results, we found the strain of the composite is less than soil, but the elastic modulus is more than soil in the same stress condition.更多还原