Research of the sensitivity of temperature and constraint factors to temperature stress in tunnel lining concrete
[Objective]The tunnel lining belongs to a thin-walled structure,and it is difficult to control the concrete temperature and prevent cracking during the construction stage.The tunnel lining of the Pearl River Delta Water Resources Allocation Project is made of C50 concrete,which is a hydraulic thin-wall concrete structure.The characteristics of adiabatic temperature rise,tem-perature rise and temperature drop quickly,and obvious constraints determine that the construction period is prone to cracks,and the problem of temperature control and crack prevention is prominent.[Methods]In response to this issue,this article relies on typical tunnel lining sections and uses three-dimensional finite element software to study the sensitivity of temperature and con-straint factors to the temperature stress of tunnel lining concrete.Based on on-site measurement data and comprehensive analysis of various factors,temperature control measures are recommended.[Results]The result show that temperature control and crack prevention measures should focus on three aspects:(1)Reducing the length of the compartment can reduce the amplitude of tem-perature stress by more than 20%,and laying geotextiles and hand hole sealing measures can significantly reduce the degree of constraint.(2)Lowering the pouring temperature of concrete can reduce temperature stress,with a decrease of 0.07 MPa/℃.(3)The temperature inside the cave remains stable,avoiding ventilation and warm water maintenance can achieve good crack pre-vention effects.[Conclusion]The research result have guided the construction of engineering sites and prevented the generation of temperature cracks.This achievement can provide reference for similar engineering construction.
water conservancy engineeringtunnel liningtemperature control and crack preventioncuring water temperaturesimulation calculationnumerical simulation
万方数据
维普
