| 摘要: |
| 混凝土力学特性受湿度影响，且存在湿胀特性，薄壁渡槽与水接触面积大，输水时间长，故其内部湿度变化而影响其性能。为研究湿度对渡槽的力学性能影响，基于Fick第二定律建立湿度扩散模型，应用物理试验率定了饱和湿度扩散系数。考虑混凝土弹性模量随湿度变化特性，以及湿胀效应，建立渡槽湿度场、变形和应力场分析模型，研究渡槽槽壁不同浸润深度对渡槽的横向、纵向变形及内力性能影响规律。结果表明，随着输水时间延长，槽壁内浸润深度沿厚度方向呈非均匀分布。湿度的扩散程度会影响渡槽的变形和应力分布规律。随浸润深度增加渡槽的纵向挠度有所增加，横向变形有所减小，横向效应大于纵向的影响程度。对于渡槽跨中横向断面来说，湿度增加了渡槽的内侧湿胀压应力，使得水分未扩散时拉应力转化为压应力，但外侧拉应力则显著增大，对槽壁外侧抗裂是不利的。对于端肋处横断面，渡槽内壁湿度增大，进一步加大了内侧压应力，对结构是有利的。 |
| 关键词: 湿度 渡槽 扩散系数 变形 内力 |
| DOI： |
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| 基金项目:国家重点研发计划资助项目（2017YFC405101-2）,国家自然科学基金项目（面上项目，重点项目，重大项目） |
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| Influence of humidity on the stress and deformation of thin-wall aqueduct |
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yangle1,2, WANG YA HONG1,2, LI ZONGLI1,3,3,2, YAO XIWANG1,2
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1.Northwest A&2.F University;3.amp
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| Abstract: |
| The mechanical properties of concrete are affected by humidity, and there is a swelling property. The thin-walled aqueduct has a large contact area with water and a long water delivery time, so its performance is affected by internal humidity changes. In order to study the influence of humidity on the mechanical properties of the aqueduct, a humidity diffusion model was established based on Fick's second law, and the saturated humidity diffusion coefficient was determined by the physical test rate. Considering the change of concrete elastic modulus with humidity and the swelling effect, the aqueduct humidity field, deformation and stress field analysis model were established, and the influence of different infiltration depth of aqueduct wall on the transverse, longitudinal deformation and internal force performance of the aqueduct was studied. The results show that as the water delivery time is extended, the infiltration depth is non-uniformly distributed along wall thickness of aqueduct. The degree of diffusion of humidity affects the deformation and stress distribution of the aqueduct. As the depth of the infiltration increases, the longitudinal deflection of the aqueduct increases, the transverse deformation decreases, and the transverse effect is greater than the longitudinal influence. For the mid-span section of the aqueduct, the humidity increases the swelling pressure of the aqueduct, so that the tensile stress is converted into compressive stress when the water is diffused, but the tensile stress is significantly increased, which is unfavorable to resistance crack of the outer wall of the aqueduct .For the transverse section of the end bearing, the humidity of the inner wall of the aqueduct increases, further increasing the inner compressive stress, which is advantageous for the structure. |
| Key words: humidity aqueduct diffusion coefficient deformation internal force |
