综合管廊早龄期混凝土温度应力仿真模拟

以汉中市综合管廊为工程背景,通过有限元软件,首先模拟分析综合管廊早龄期温度场,随后将温度场结果附加到管廊结构中求解温度应力,从而分析综合管廊早龄期混凝土温度应力与浇筑长度的关系。模拟分析发现:综合管廊在混凝土浇筑早期,温度场沿长度方向变化不显著,且随着浇筑长度的增加,温度场不变;在墙体温度上升阶段,墙体内部沿长度方向的应力主要为压应力,当墙体混凝土内部温度达到最高,混凝土开始降温,结构内变形由膨胀逐渐变为收缩,内力由压应力逐渐变为拉应力,随着时间的变化,墙体内外温差趋于稳定,墙体温度应力也逐渐平稳,此时温度应力主要受外界环境变化影响;当综合管廊浇筑长度在60m范围内,浇筑长度越大,温度应力越大,但当浇筑长度超过60m,温度应力不再增加。

Simulation of temperature stress of early-age concrete of utility tunnel

Hydration heat is produced during cement hydration,which is an important reason for early cracks in concrete structures.Based on the engineering background of Hanzhong utility tunnel,the temperature field and temperature stress of early-age concert of the utility tunnel are simulated,and the relationship between temperature stress and casting length of early-age concrete of utility tunnel is analyzed.The simulation analysis shows that thetemperature field of the utility tunnel changes little along the length direction in the early stage of concrete casting,and the temperature field remain unchanged with the increase of casting length.In the early stage of concrete casting,in the rising stage of wall temperature,the internal pressure stress of wall is mainly compressive stress.When the internal temperature of wall concrete reaches the highest,the concrete begins to cool down,the deformation in the structure gradually changes from expansion to contraction,and the internal force gradually decreases from compressive stress to tensile stress.With the change of time,the temperature difference of concrete inside and outside the wall tends to be stable,and the temperature stress of the wall also gradually becomes stable.At this time,the temperature stress is mainly affected by the change of the external environment.When the length of the utility tunnel is within a certain range,the longer the length is,the greater the temperature stress will be.