超长地下室墙体环境温度应力分析与裂缝控制
发布时间：2019-06-18 11:42
【摘要】：随着经济的迅猛发展以及工程技术的不断进步,一大批超长混凝土结构不断涌现出来,而建筑物由于受到季节温度变化的影响,产生裂缝十分常见,并且地下建筑有防水要求,一旦墙板开裂造成渗漏其危害性很大。所以,对混凝土结构裂缝控制的问题,成为现今关注的重点。本文首先介绍了关于超长混凝土结构温度场和温度应力的基本理论。其次,本文以沈阳市环境温度为研究背景,采用环境温度应力分析理论,借助ANSYS有限元软件,运用三维有限元模型线弹性分析方法,建立超长地下室结构简化模型。在进行超长地下室结构简化模型环境温度作用分析时,所施加的温度荷载主要是气温骤降下的室内外最不利温差,不考虑其收缩的影响。然后进行有限元线弹性分析,得出了墙板内的温度应力分布规律。并进一步研究分析了墙长、墙高、墙厚、覆土厚度、内外温差以及混凝土强度变化对地下室墙板温度应力的产生范围和分布规律的影响。在上述工作的基础上取得的研究成果主要有：(1)地下室侧墙,沿墙体长度方向墙体为中截面温度应力大,并向两端逐渐减小分布,而沿高度方向则为下部大向上逐渐减小分布,并且短墙的温度应力很小。经分析得温度应力易出现在尺寸较长的方向上。底板应力集中在板中央向四周扩散,一般为压应力,较不容易出现裂缝；(2)温度应力随墙长逐渐增加,但是最后趋近于一个定值(3)随墙体高度的增加,温度应力逐渐减小,即墙体高度和最大应力成反比；(4)随墙体厚度的增加温度应力逐渐减小,底板对薄墙的约束较大,所以墙体越薄对温度应力越敏感。根据此规律,可对薄墙采取一定的保温措施,从而减小温度拉应力；(5)覆土对地下室墙体具有保温隔热的作用,能减少环境温度应力对结构的影响；(6)在墙体长度为30m时,改变其温差得知,在温差较小时墙体的应力在整个墙体上变化不大。当温差大于40℃时,墙体从30m～100m最大的温度应力值一般都大于混凝土抗拉强度标准值。因此对温差的控制对地下室墙体很重要；(7)混凝土强度越高则结构受环境温度效应影响就越敏感产生的温度应力就越大。最后,本文从分析结果出发,在材料、设计构造以及施工措施等方面介绍了地下室超长混凝土结构裂缝控制的一些技术措施。
[Abstract]:With the rapid development of economy and the continuous progress of engineering technology, a large number of super-long concrete structures continue to emerge, and due to the influence of seasonal temperature changes, cracks are very common in buildings, and underground buildings have waterproof requirements, once the crack of wallboards causes great harm to leakage. Therefore, the crack control of concrete structures has become the focus of attention. In this paper, the basic theory of temperature field and temperature stress of super-long concrete structure is introduced. Secondly, based on the environmental temperature of Shenyang, the simplified model of super-long basement structure is established by using the theory of ambient temperature stress analysis, with the help of ANSYS finite element software and the linear elastic analysis method of three-dimensional finite element model. In the analysis of the ambient temperature action of the simplified model of super-long basement structure, the temperature load applied is mainly the most unfavorable temperature difference between indoor and outdoor under the sudden drop of temperature, regardless of the influence of shrinkage. Then the finite element linear elastic analysis is carried out, and the distribution law of temperature stress in the wallboard is obtained. The effects of wall length, wall height, wall thickness, overlying soil thickness, internal and external temperature difference and concrete strength on the generation range and distribution of temperature stress of basement wall panel are further studied and analyzed. On the basis of the above work, the main research results are as follows: (1) in the basement side wall, the temperature stress of the middle section is large along the length of the wall, and the distribution decreases gradually to both ends, while the distribution decreases gradually along the height direction, and the temperature stress of the short wall is very small. It is found that the temperature stress is easy to appear in the direction of long size. The stress of the floor is concentrated in the center of the plate and diffuses around, generally compressive stress, which is not easy to crack. (2) the temperature stress increases gradually with the length of the wall, but finally approaches a fixed value (3) with the increase of the height of the wall, the temperature stress decreases gradually, that is to say, the height of the wall is inversely proportional to the maximum stress; (4) with the increase of the thickness of the wall, the temperature stress decreases gradually, and the constraint of the bottom plate to the thin wall is greater, so the thinner the wall is, the more sensitive it is to the temperature stress. According to this law, some thermal insulation measures can be taken for the thin wall, so as to reduce the temperature tensile stress; (5) the overlying soil has the effect of heat preservation and heat insulation on the basement wall, which can reduce the influence of the ambient temperature stress on the structure; (6) when the length of the wall is 30m, the temperature difference of the wall shows that the stress of the wall does not change much on the whole wall when the temperature difference is small. When the temperature difference is more than 40 鈩，
本文编号：2501461
[Abstract]:With the rapid development of economy and the continuous progress of engineering technology, a large number of super-long concrete structures continue to emerge, and due to the influence of seasonal temperature changes, cracks are very common in buildings, and underground buildings have waterproof requirements, once the crack of wallboards causes great harm to leakage. Therefore, the crack control of concrete structures has become the focus of attention. In this paper, the basic theory of temperature field and temperature stress of super-long concrete structure is introduced. Secondly, based on the environmental temperature of Shenyang, the simplified model of super-long basement structure is established by using the theory of ambient temperature stress analysis, with the help of ANSYS finite element software and the linear elastic analysis method of three-dimensional finite element model. In the analysis of the ambient temperature action of the simplified model of super-long basement structure, the temperature load applied is mainly the most unfavorable temperature difference between indoor and outdoor under the sudden drop of temperature, regardless of the influence of shrinkage. Then the finite element linear elastic analysis is carried out, and the distribution law of temperature stress in the wallboard is obtained. The effects of wall length, wall height, wall thickness, overlying soil thickness, internal and external temperature difference and concrete strength on the generation range and distribution of temperature stress of basement wall panel are further studied and analyzed. On the basis of the above work, the main research results are as follows: (1) in the basement side wall, the temperature stress of the middle section is large along the length of the wall, and the distribution decreases gradually to both ends, while the distribution decreases gradually along the height direction, and the temperature stress of the short wall is very small. It is found that the temperature stress is easy to appear in the direction of long size. The stress of the floor is concentrated in the center of the plate and diffuses around, generally compressive stress, which is not easy to crack. (2) the temperature stress increases gradually with the length of the wall, but finally approaches a fixed value (3) with the increase of the height of the wall, the temperature stress decreases gradually, that is to say, the height of the wall is inversely proportional to the maximum stress; (4) with the increase of the thickness of the wall, the temperature stress decreases gradually, and the constraint of the bottom plate to the thin wall is greater, so the thinner the wall is, the more sensitive it is to the temperature stress. According to this law, some thermal insulation measures can be taken for the thin wall, so as to reduce the temperature tensile stress; (5) the overlying soil has the effect of heat preservation and heat insulation on the basement wall, which can reduce the influence of the ambient temperature stress on the structure; (6) when the length of the wall is 30m, the temperature difference of the wall shows that the stress of the wall does not change much on the whole wall when the temperature difference is small. When the temperature difference is more than 40 鈩，
本文编号：2501461
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