《Journal of Performance of Constructed Facilities 》杂志刊登“北方地区混凝土坝的季节性温度裂缝”

作  者：Dolice Dontsi Maken, Pierre Léger, Simon-Nicolas Roth

刊  物：《Journal of Performance of Constructed Facilities》，2013年6月印刷

关键词：混凝土坝，温度裂缝，有限元模型，热力学行为

摘  要：在世界各地寒冷的北方地区，季节性温度变化严重影响混凝土坝，冬夏的温度差高达75°C。较大温度差引起了混凝土坝的刚度、强度和耐久性的退化。因此需要对热应力及相关的混凝土开裂进行评估，以确保大坝的结构稳定性和确定异常或极端荷载（如洪水和地震）组合的初始条件。本文提出了有限元建模程序来评估混凝土坝的热力学行为。通过考虑简单缺口梁模型的热力学响应获得了混凝土的初始温度，应力松弛和力学性能取决于混凝土的初始温度。并对位于加拿大的31米的混凝土重力坝和214米连拱坝进行传热和热力学分析。结果表明，与温度相关的材料特性对大坝结构响应的影响并不显著。所提出的数值模型成功地再现了存在于连拱坝下游面的斜裂缝。最后讨论了利用等效线性连续混凝土的本构模型进行有关开裂拱柔韧性建模的问题。

Seasonal Thermal Cracking of Concrete Dams in Northern Regions

Authors: Dolice Dontsi Maken, Pierre Léger, Simon-Nicolas Roth

Journal: Journal of Performance of Constructed Facilities, Published: 06 June 2013

Key words: concrete dams, thermal cracking, finite element modeling, thermo-mechanical behaviors

Abstract: In several northern regions around the world, concrete dams are subjected to severe seasonal temperature variations, with up to 75°C changes from summer to winter. Those variations contribute to the degradation of the stiffness, strength, and durability of concrete dams. Thermal stresses and related concrete cracking also need to be evaluated to ensure the structural stability of the dam and to define the initial conditions for unusual or extreme load combinations, such as floods and earthquakes. This paper presents finite element modeling procedures for assessing the thermo-mechanical behaviors of concrete dams. The stress relaxation and mechanical properties that depend on the temperature of the concrete are first investigated by considering the thermo-mechanical responses of simple notched beam models. Heat transfer and thermo-mechanical analyses are then presented for a 31-m concrete gravity dam and a 214-m multiple arch dam located in Canada. It is shown that temperature-dependent material properties do not significantly affect the structural response of the dam. Oblique cracks present on the downstream face of the multiple arch dam are successfully reproduced by the proposed numerical model. Modeling of the related cracked arch flexibility using equivalent linear continuum concrete constitutive models is also discussed.

原文链接：http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29HE.1943-5584.0000722