机敏土工带的研制及其性能研究

发布时间：2018-06-28 19:38

本文选题：机敏土工带 + 拉敏效应　；参考：《山东大学》2017年硕士论文

【摘要】：伴随着土工合成材料日益广泛的应用及各领域需求的不断提高,对其性能的要求也愈加严苛。土工格栅作为土工合成材料的一种,因其优异的性能被广泛应用于各类加筋土工程中,然而单一的加固功能已经难以满足日益复杂工程的需求,也无法对加筋土工程内部变形及破坏进行及时的监测预警,以避免安全事故的发生。因此,寻找安全有效地监测预警方法具有重要意义。本文基于导电高分子复合材料的拉敏效应,通过特定的生产工艺制作传感型土工格栅,使其兼具加固及监测预警双重功能,同时以传感型土工格栅为研究对象,结合前期大量的室内试验及理论分析,为实现其加固及监测双重功能,进行了如下方面的研究:(1)针对前期研制的传感型土工格栅强度小、韧性低、电阻难以测量的问题,改进了格栅的生产方法与工艺,创新性的研制成功传感型的机敏土工带(后简称机敏带),具备较高的强度、韧性及准确可靠的电阻测量值,并确定机敏带基本的物理力学性能。结果表明,随炭黑含量的增加机敏带强度逐渐降低;蠕变曲线为典型衰减型,相同时间内炭黑含量越高蠕变变形较大;不同炭黑含量机敏带的摩擦角及表观粘聚力近似相等。(2)针对机敏带电阻稳定性及拉敏性,研究了尺寸、温度及应力松弛因素的影响,结果发现:不同试样尺寸,归一化电阻随应变呈现出近似线性的增长趋势,且长度尺寸越大,相同应变下归一化电阻随越大,即应变灵敏度越高;机敏带的归一化电阻-温度曲线呈现出典型的PTC效应,常温下机敏带具有良好的电阻稳定性,温度大于90℃后电阻增大显著;机敏带的应力保持率-时间曲线符合典型的Maxwell模型,开始应力降低速度快,随后速度变慢,测定时间内电阻保持率在75%以上,表现出较好的稳定性。(3)模拟研究了地震疲劳作用下机敏带的抗疲劳性能,结果发现:机敏带的疲劳断裂循环次数随炭黑含量的增大而减小、随着应变的增大而减小;疲劳后,机敏带的强度保持率随应变及震级的升高逐渐降低,机敏带的拉敏性能出现灵敏度升高的现象。(4)室内试验研究了机敏带的耐老化性能,分析了机敏带在经历热氧老化以及光老化后性能指标的变化,发现:经历老化后机敏带出现脆性变化,其强度及断裂伸长率均发生降低,机敏带热氧老化后的拉敏性能保持稳定,光老化后出现提升。(5)室内试验研究了机敏带的耐腐蚀性能,结果发现:酸碱溶液腐蚀后机敏带的强度和断裂伸长率均出现降低,降低幅度与浸泡时间成正相关;酸碱腐蚀后机敏带的拉敏性能愈加明显,但随浸泡时间的增长变化较小。
[Abstract]:With the increasing application of geosynthetics and the increasing demand in various fields, the requirements for its performance are becoming more stringent. Geosynthetics, as a kind of geosynthetics, are widely used in all kinds of reinforced soil engineering because of their excellent properties. However, the single consolidation function has been difficult to meet the needs of increasingly complex engineering. In order to avoid the timely monitoring and early warning of the internal deformation and failure of reinforced soil engineering, it is of great significance to find safe and effective monitoring and early warning method. Based on the sensitive effect of the conductive polymer composite material, the sensing geogrid is made by a specific production process to make it concurrently With the dual functions of strengthening and monitoring and warning, and taking the sensing geogrid as the research object, combined with a large number of laboratory tests and theoretical analysis in the earlier period, the following research has been carried out to realize the dual functions of its reinforcement and monitoring. (1) the problems of small strength, low toughness and difficulty in measuring the resistance of the sensing geogrid are improved. The production method and process of the grille, innovative development of the sensitive geotextile belt (after short), has high strength, toughness and accurate and reliable resistance measurement value, and determine the basic physical and mechanical properties of the sensitive belt. The results show that the strength of the sensitive belt decreases with the increase of the content of carbon black; the creep curve is the canon. The higher the carbon black content in the same time, the higher the creep deformation, the friction angle and the apparent cohesion of the sensitive belt with different carbon black are approximately equal. (2) according to the resistance stability and the sensitivity of the sensitive belt, the influence of the dimensions, temperature and stress relaxation factors is studied. The results show that the size of different specimens and the normalized resistance are presented with the strain. The higher the linear growth trend, the larger the length size, the greater the normalized resistance under the same strain, the higher the strain sensitivity; the normalized resistance temperature curve of the sensitive belt shows a typical PTC effect. The resistance stability of the sensitive belt at normal temperature is good, the temperature is larger than 90 C, the resistance increases significantly, and the stress retention rate of the sensitive belt is - The time curve conforms to the typical Maxwell model, the beginning of the stress reduction is faster, then the speed is slower, the resistance retention rate in the measured time is above 75%, and the stability is better. (3) the fatigue performance of the sensitive zone under the action of earthquake fatigue is studied. The results show that the fatigue fracture cycle times of the sensitive belt increase with the content of carbon black. And it decreases with the increase of strain; after fatigue, the strength retention of the sensitive belt gradually decreases with the increase of strain and magnitude, and the sensitivity of the sensitized belt increases. (4) the aging resistance of the sensitive belt is studied in the laboratory and the performance indexes of the sensitive zone after thermal oxygen aging and photoaging are analyzed. It is found that the sensitivity of the sensitive belt changes after the aging, and the strength and elongation at break all decrease. The sensitivity of the sensitive zone is stable after the aging of the hot oxygen. (5) the corrosion resistance of the sensitive zone is studied in the laboratory. The results are as follows: the strength and elongation of the acidity zone after acid alkali solution corrosion All of them decreased and the reduction rate was positively correlated with immersion time. The sensitivity of the sensitive belt after acid and alkali corrosion was more obvious, but it changed little with the increase of soaking time.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU531.7

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