复杂环境因素关联下路基平衡湿度状态精细表征

发布时间：2018-01-14 18:23

本文关键词：复杂环境因素关联下路基平衡湿度状态精细表征　出处：《重庆交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：回弹模量和永久变形是沥青路面“力学—经验”设计法中表征路基力学性状的重要参数，其值随着路基湿度和温度环境因素的变化而改变，因此，路面结构设计应充分考虑路基湿度实际所处状态及变化特征。本文采取文献调研、数值模拟、现场调查、理论分析等多种技术手段，以“土-水特性曲线——基质吸力——路基湿度——路基性能”为研究主线，详细探讨降雨环境和地下水位升降情况下路基湿度变化规律，建立了不同环境因素主导下的路基湿度预估模型，分析了路基湿度对路基性能的影响，主要研究工作如下： ①通过广泛国内外文献调研，，结合路基湿度现场调研的结果，明确路基湿度在运营3-5年达到平衡，应该以平衡湿度作为路基湿度设计状态。综合路基湿度来源及各种影响因素，将其归并为气候与地下水位两大控制因素，气候因素中大气降雨占主导地位。 ②用SEEP/W软件进行数值模拟，详细分析降雨强度、降雨历时、路面类型、路基路面裂隙条件下路基湿度的变化规律。结果表明：1）路面不透水条件下，土路肩、边坡、中央分隔带是雨水入渗的主要途径，在路基内部形成弧形扰动区；2）降雨历时一定条件下，扰动范围与降雨强度呈正比例函数关系，扰动范围路基土的体积含水量与降雨强度呈对数函数关系；3）降雨强度一定条件下，扰动范围路基土体积含水量与降雨历时符合对数函数关系；4）路面透水情况下，受降雨影响最大的是路床和上路堤区域，下路堤区域所受影响较小，路面中心下路基湿度扰动深度随时间的增长呈线性扩散的规律；5）路基路面存在裂隙情况下，对于降雨强度小于材料渗透系数的无积水的降雨，整个非饱和路基湿度场没有明显变化；有积水的强降雨，非饱和路基渗流场将会发生显著改变；6）路基裂隙周围路基湿度扰动范围随着时间的增长呈线性扩散。 ③用SEEP/W软件进行数值模拟，详细分析地下水位升降条件下路基湿度的变化规律。结果表明：1）在地下水位不变的情况下，随着时间的延长，地下水对路基湿度的扰动范围逐渐增大，最终趋于平衡，达到毛细上升最大高度；2）地下水对路基湿度场的影响范围有限，压实度为96%的粉质粘土的毛细水最大上升高度为6.75m，扰动距离随时间的变化符合关系式D at2bt的规律；3）地下水位回落过程，路基土体积含水量与时间的符合关系式m ae btv c的规律。 ④根据路基湿度主要影响因素的不同，将路基划分为3种型类。分别提出了适合Ⅰ型类路基湿度预估的TMI wPI模型和完善了预估Ⅲ型类路基湿度的地下水位模型，给出了路基湿度预估的流程。 ⑤对3种土样进行室内重复加载三轴试验，测试内容包括路基土常规动回弹模量、永久变形，结果表明：各类路基土回弹模量对含水量变化非常敏感，同时含水率越高，永久变形越大。
[Abstract]:Resilient modulus and permanent deformation of asphalt pavement is "mechanical design experience" in suhgrade and mechanical properties of the important parameters, the value with the change of subgrade humidity and temperature environmental factors change, therefore, the pavement structure design should fully consider the actual state of the subgrade humidity and variation.
This paper adopts literature research, numerical simulation, field investigation, theoretical analysis of a variety of technical means, to the soil water characteristic curve, the matrix suction, the subgrade humidity - subgrade performance "as the main line, with changes of the subgrade humidity rainfall and underground water level lifting environment, established a prediction model of Subgrade humidity leading to different environmental factors the influence of humidity on Subgrade subgrade performance, the main research work is as follows:
Through extensive literature survey, combined with the subgrade humidity field investigation, clear the subgrade humidity in operation 3-5 years to reach equilibrium, should be to balance the subgrade humidity humidity as design state. Factors and various effects of subgrade humidity origin, they are merged into the climate and groundwater level two control factors, climate factors accounted for rainfall the leading position.
Using SEEP/W software to simulate the detailed analysis of rainfall intensity, rainfall duration, pavement type, variation of subgrade humidity of subgrade and pavement crack conditions. The results show that: 1) impervious pavement conditions, soil shoulder, slope, central zone is the main path of rainwater infiltration, forming an arc disturbed zone in subgrade internal; 2) rainfall duration under certain conditions, the disturbance range and the rainfall intensity was positively proportional to the perturbation range, subgrade soil moisture was logarithmic function relationship with rainfall intensity; 3) rainfall intensity under certain conditions, the perturbation range of the subgrade soil moisture and rainfall duration with logarithmic function; 4) permeable pavement under the condition, affected by rainfall is the largest area under the roadbed and embankment, embankment region is less affected, the central road under the subgrade humidity disturbance depth increase with time linear diffusion; 5) pavement cracks are under no water for the rainfall intensity is less than the material permeability coefficient of rainfall, the unsaturated subgrade humidity field has no obvious change; heavy rainfall water, unsaturated seepage flow field will be changed obviously subgrade; 6) subgrade cracks around the subgrade humidity disturbance range with the increase of time is linear diffusion.
Using SEEP/W software to simulate the variation of subgrade humidity with analysis of underground water level fluctuation conditions. The results show that: 1) in the same under the situation of underground water level, with the extension of time, the perturbation range of groundwater on Subgrade humidity increases, eventually tends to balance, the maximum rising height of capillary water; 2) effect on Subgrade humidity field of limited scope, 96% degree of compaction of the silty clay the maximum rising height of capillary water is 6.75m, distance of disturbance changes over time in line with the relation of D at2bt law; 3) underground water fall process, subgrade soil volume water content and time with m AE BTV C the law.
4. According to the difference of main influence factors of roadbed humidity, the roadbed is divided into 3 types. A TMI wPI model suitable for type I subgrade humidity prediction is proposed, and a groundwater level model for predicting type III roadbed humidity is perfected, and the prediction process of subgrade humidity is given.
3 indoor repeated loading three axis tests were carried out. The test contents include routine dynamic modulus of elasticity and permanent deformation of subgrade soil. The results show that resilient modulus of all kinds of subgrade soil is very sensitive to the change of water content, and the higher the moisture content, the greater the permanent deformation.

【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.1

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