地面式钢筋混凝土水池自愈、渗漏试验及地震响应分析

发布时间：2018-10-14 12:40

【摘要】：钢筋混凝土水池在供水系统中承担着净水、储水的重要功能,是典型的储液结构。裂缝的出现会加速钢筋锈蚀、降低结构耐久性,且结构设计中裂缝宽度限值很大程度上决定了配筋量。水池在地震作用下易出现裂缝,裂缝可能导致储液渗漏,造成水池服务功能下降甚至丧失,并在一定程度上影响整个系统的功能。震后储液结构的裂缝开展情况及由此导致储液渗漏程度是评判水池地震破坏等级的主要标准。目前,已有研究成果表明,混凝土裂缝在与水接触条件下会发生自愈使原有裂缝宽度减小,水池由于储水为裂缝的自愈提供了必要条件。因此,应考虑承载力、耐久性、服务功能、经济性、裂缝自愈性能及震后维修加固可行性等因素综合确定水池结构设计和地震破坏等级划分标准中的裂缝限值。储液结构在地震作用下存在液固耦合效应且液体会发生晃动,储液的存在改变了结构的动力特性和地震响应。水池结构除受到结构本身惯性力和静水压力外,其底部和侧壁还承受液体在垂直壁面方向上产生的动水压力。水池在抗震设计中需考虑液面晃动和动水压力的影响。现阶段,对钢筋混凝土水池裂缝自愈性能、渗漏特性及水池在地震作用下的液固耦合动力特性和地震响应的研究尚不完善。本文通过钢筋混凝土水池壁板弯曲裂缝和贯通裂缝自愈、渗漏试验研究混凝土裂缝的自愈性能及渗漏特性,采用大型有限元软件ADINA进行圆形水池地震响应分析,研究液固耦合系统的动力特性、储液晃动、动水压力及破坏特征等。论文主要完成了如下工作:(1)设计并完成了钢筋混凝土水池壁板弯曲裂缝和贯通裂缝的自愈及渗漏试验。进行了材料性能试验;对静水环境中弯曲微裂缝、流动水环境中贯通裂缝的自愈性能进行了测试,给出了弯曲微裂缝在静水环境中短期内的自愈合宽度,证实了贯通裂缝在流动水环境中仍会发生自愈合;在裂缝上施加实际水头作用测试了弯曲裂缝和贯通裂缝的渗漏特性,研究了弯曲裂缝宽度、受压区高度及作用水头对液体渗漏的影响,分析了贯通裂缝水的渗漏率与累计时间和水头高度之间的关系。通过试验得到裂缝特性与自愈及渗漏之间的关系,为水池结构设计和地震破坏等级划分提供参考。(2)对地面式圆形水池进行了液固耦合动力特性分析,液固耦合系统包括刚体模态、储液晃动模态和液固耦联振动模态3种形式。研究了储水高度、水池半径、液体表面重力波对液固耦合系统动力特性的影响。此外,对比了圆形水池储液晃动频率的理论和有限元计算结果,验证了模型的可靠性,且推导得到圆形水池储液晃动基本周期计算公式。(3)分析了单向水平地震作用下不同水池半径、不同储水高度圆形水池的液面最大晃动波高,拟合得到了圆形水池单向地震作用下的液面最大晃动波高计算公式。公式可用于储液结构地震作用下的最大晃动波高估计和储液结构最大晃动波高设计。结合储液结构长周期抗震设计反应谱和阻尼比修正系数,提出了储水水池液面最大晃动波高计算方法。(4)研究了单向水平地震作用下,不同水池半径、不同储水高度圆形水池池壁、底板环向和径向位置的动水压力数值及分布情况,并与理论计算结果进行了对比;分析了地震动峰值加速度、储水高度、水池半径对动水压力的影响;确定了对流压力与脉冲压力的叠加方法;拟合得到对流压力、脉冲压力及动水压力计算公式;结合底板环向动水压力分布,综合给出单向水平地震作用下圆形水池动水压力标准值,与较复杂的理论计算方法和仅考虑脉冲压力的规范法相比,计算更简便且与实际相符。此外,还分析了液面和池底动水压力的时程变化。(5)进行了双向水平地震动作用下圆形水池的地震响应分析,提取了液面最大晃动波高和动水压力计算结果;基于单向水平地震动作用下的响应结果,通过合理的组合方式给出了双向水平地震动作用下的液面最大晃动波高和动水压力计算公式,建立了双向水平地震作用下储水水池液面最大晃动波高和动水压力计算方法;并对双向水平地震作用下圆形水池地震破坏特征和易损性进行了分析。
[Abstract]:The reinforced concrete pool has the important function of water purification and water storage in the water supply system, and it is a typical liquid storage structure. The occurrence of cracks will accelerate the corrosion of the steel bars, reduce the structural durability, and determine the amount of reinforcement in the structural design to a great extent. The water pool is prone to crack under the action of earthquake, which may lead to the leakage of the reservoir, which may cause the deterioration and even loss of the service function of the pool, and to some extent affect the function of the whole system. The crack development of reservoir structure after earthquake and the degree of leakage of reservoir are the main criteria for judging the seismic damage grade of pool. At present, the research results show that self-healing of concrete crack under the contact with water makes the width of the original crack decrease, and the water reservoir provides the necessary condition for self-healing of the crack due to water storage. Therefore, consideration should be given to the factors such as bearing capacity, durability, service function, economy, crack self-healing property and feasibility of post-earthquake maintenance and reinforcement. The liquid storage structure has a liquid-solid coupling effect under the action of earthquake and sloshing of the liquid, and the existence of the reservoir changes the dynamic characteristics and the seismic response of the structure. in addition to that inertia force and hydrostatic pressure of the structure itself, the basin structure also bear the dynamic water pressure generated in the vertical wall surface direction of the liquid in the vertical wall surface direction. The water pool needs to consider the influence of liquid level sloshing and dynamic water pressure in anti-seismic design. At the present stage, it is not perfect to study the self-healing properties, leakage characteristics and the hydrodynamic characteristics of liquid-solid coupling and seismic response of the pool under earthquake action. In this paper, the self-healing properties and leakage characteristics of concrete cracks are studied by bending crack and through-crack self-healing and leakage test of reinforced concrete pool wall plate, and large-scale finite element software ADINA is used to analyze the seismic response of circular pool. The dynamic characteristics of liquid-solid coupling system and the sloshing of reservoir are studied. Dynamic water pressure and destruction characteristics, etc. The paper mainly completes the following work: (1) design and complete the self-healing and leakage test of the bending crack and the through crack of the reinforced concrete pool wall panel. In this paper, the self-healing properties of penetrating cracks in micro-cracks and flowing water environment are tested. The self-healing width of the micro-cracks in the short term is given, and the self-healing of the through-cracks in the flowing water environment is confirmed. The leakage characteristics of bending crack and through-crack are tested by applying the actual water head on the crack, and the influence of the bending crack width, the height of the compression zone and the water head on the leakage of the liquid is studied, and the relationship between the leakage rate of the through-crack water and the accumulated time and the head height is analyzed. The relationship between fracture characteristic and self-healing and leakage is obtained by experiment, which provides reference for the design of pool structure and classification of earthquake damage grade. (2) Fluid-solid coupling dynamic characteristic analysis is carried out on the ground circular pool, and the liquid-solid coupling system includes three types of rigid-body mode, liquid storage sloshing mode and liquid-solid coupling vibration mode. The influence of water storage height, pool radius and gravity wave on the dynamic characteristics of liquid-solid coupling system was studied. In addition, the theoretical and finite element calculation results of the sloshing frequency of the circular pool reservoir are compared, the reliability of the model is verified, and the calculation formula of the basic period of sloshing the reservoir of the circular pool is derived. (3) The maximum sloshing wave height of the circular pool with different water storage heights under the action of one-way horizontal earthquake is analyzed, and the calculation formula of the maximum sloshing wave height of the liquid surface under the one-way earthquake action of the circular pool is obtained. The formula can be used for the maximum sloshing wave height estimation and the maximum sloshing wave height design of the liquid storage structure under the earthquake action of the liquid storage structure. In this paper, the maximum sloshing wave height calculation method for the liquid level of the water storage tank is put forward in combination with the long-period anti-seismic design reaction spectrum of the liquid storage tank and the correction coefficient of the water storage tank. (4) The numerical value and distribution of dynamic water pressure at different pool radius, different water storage height circular pool, bottom plate ring and radial position under one-way horizontal earthquake are studied, and compared with the theoretical calculation results, the peak acceleration and water storage height of ground motion are analyzed. The influence of pool radius on dynamic water pressure is determined; the superposition method of convective pressure and pulse pressure is determined; the calculation formula of convection pressure, pulse pressure and dynamic water pressure is obtained by fitting; combined with the distribution of dynamic water pressure of bottom plate ring, The standard value of dynamic water pressure of circular pool under the action of one-way horizontal earthquake is given, and compared with the complicated theoretical calculation method and the standard method considering only pulse pressure, the calculation is more convenient and consistent with reality. In addition, the time-course change of the dynamic water pressure at the liquid level and the bottom of the tank was also analyzed. and (5) carrying out the seismic response analysis of the circular water tank under the action of bi-directional horizontal vibration, extracting the calculation result of the maximum sloshing wave height and the dynamic water pressure of the liquid surface, The maximum sloshing wave height and dynamic water pressure calculation formula of the liquid surface under two-way horizontal earthquake are given by reasonable combination method, and the calculation method of maximum sloshing wave height and dynamic water pressure of the water storage tank under the action of bi-directional horizontal earthquake is established. The seismic damage characteristics of circular pool under the action of bi-directional horizontal earthquake are also analyzed.
【作者单位】：中国地震局工程力学研究所;
【分类号】：TU991.343;TU375

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