港珠澳大桥沉管隧道早期应力参数化分析与裂缝控制

根据港珠澳跨海大桥沉管隧道结构抗裂抗渗及耐久性需要,对管节大体积混凝土进行了早期温度-应力有限元仿真分析。据此预测管节在施工中可能出现混凝土表面开裂或出现截面拉裂的最危险时间和最不利位置。计算结果表明,由于高强混凝土的采用以及管壁厚度达1.35 m,裂缝发生和扩展的最危险时段为36-144 h;而管节作为复杂截面其表面应力的分布也复杂化,在截面转角处、受约束较大处是裂缝发生的最危险位置。通过对影响沉管温度应力的不同的材料参数、水化热参数、施工参数、养护参数进行多次反复的有限元参数化分析,探讨了各种参数的影响,并为寻求科学合理的温度控制、裂缝控制解决方案提供理论依据。

Early stress parameter analysis and crack control to Hong Kong-Zhuhai-Macao Bridge immersed tube tunnel

According to Hong Kong-Zhuhai-Macao Bridge immersed tube tunnel about the crack resistence and impermeability and durability needed,the early temperature-stress Finite Element Analysis for mass concrete of the tube.To predict pipe section may be in the construction of the concrete surface cracking or crack appears the most dangerous section of the time and the most unfavorable position.The results show that,Since the adoption of high-strength concrete and the wall thickness of 1.35 m,Cracks expanded and occurred in the most dangerous time is 36 h to 144 h.The pipe section as the surface of complex cross section is also complicated by the stress distribution,In the section corner,is bound by the larger cracks occurred at the location of the most dangerous.Through finite element parametric analysis of different material parameters、hydration heat parameters、construction parameters and the conservation parameters that influencing temperature-stress of the immersed tube repeatedly,discussed the influence of various parameters,and provided a classical thought for seeking the scientific and reasonable solution about temperature control and crack control.