Based on the Wuhan Yangtse River Tunnel Project, the low-penetration fiber concrete used in the protecting layer of Wuhan Yangtse River Tunnel tube has been studied in this paper. With the effect of silica fume, slag ...Based on the Wuhan Yangtse River Tunnel Project, the low-penetration fiber concrete used in the protecting layer of Wuhan Yangtse River Tunnel tube has been studied in this paper. With the effect of silica fume, slag and polypropylene fiber on the anti-penetration of tunnel concrete by means of NEL test, XRD and SEM, some conclusions has been drawn. The affection on the anti-penetration capability of the four factors is capacity of silica fume>portion of short and long fiber> fiber VOL Portion>length of Fiber. Fiber capacity of 0.15% is still not good enough for the anti-penetration capability of concrete. While that of 0.5% has exceed the maximum, and the fiber tends to assemble together. Silica fume may greatly enhance the anti-penetration capability of concrete, while the relationship between them is not direct proportion. The average of chloric ion pervasion coefficient with 8% capacity of silica fume is the lowest. Slag may reacted with other component to generate lots of C-A-H. When reacted with free chloride ion, C-A-H may form friedel salt which may also enhance the Anti-penetration capability of concrete.展开更多
为了防止和减少隧道渗漏水病害,通过分析复合式衬砌隧道防排水的现状和存在的主要问题,研究隧道排水量和水压力控制值分级、上下分离的防排水体系、围岩防水能力、防水层和二次衬砌混凝土整体防水效果检验评价等,并对防排水系统的设计...为了防止和减少隧道渗漏水病害,通过分析复合式衬砌隧道防排水的现状和存在的主要问题,研究隧道排水量和水压力控制值分级、上下分离的防排水体系、围岩防水能力、防水层和二次衬砌混凝土整体防水效果检验评价等,并对防排水系统的设计和参数选择提出以下建议:1)对于采用复合式衬砌的隧道,如果能满足环境保护及使用功能要求,其全隧道排水量宜控制在1.0 m 3/(m·d)以内,二次衬砌背后承受的水压力最大宜控制在1.0 MPa以内;2)为了减少隧道渗漏水发生的概率,并保证隧道结构的稳定,可考虑将拱、墙防排水体系和仰拱防排水体系分开设置,拱部、侧墙部位的渗水直接排入侧沟,仰拱部位的水主要通过纵向中心排水盲管排出,当水压力高时,通过与中心排水盲管连通的横向排水管将水引入新增的侧沟,并通过在横向排水管出水口安装的阀门进行限量排放;3)通过地面隔离墙(咬和桩)、地面注浆、洞内注浆、旋喷、超前管棚、超前管幕、施作双层衬砌等措施,阻断和减小来水通道,提高地层强度和完整性,降低隧道涌水量和衬砌背后的水压力,并降低大量排水对运营和环境的不利影响。展开更多
文摘Based on the Wuhan Yangtse River Tunnel Project, the low-penetration fiber concrete used in the protecting layer of Wuhan Yangtse River Tunnel tube has been studied in this paper. With the effect of silica fume, slag and polypropylene fiber on the anti-penetration of tunnel concrete by means of NEL test, XRD and SEM, some conclusions has been drawn. The affection on the anti-penetration capability of the four factors is capacity of silica fume>portion of short and long fiber> fiber VOL Portion>length of Fiber. Fiber capacity of 0.15% is still not good enough for the anti-penetration capability of concrete. While that of 0.5% has exceed the maximum, and the fiber tends to assemble together. Silica fume may greatly enhance the anti-penetration capability of concrete, while the relationship between them is not direct proportion. The average of chloric ion pervasion coefficient with 8% capacity of silica fume is the lowest. Slag may reacted with other component to generate lots of C-A-H. When reacted with free chloride ion, C-A-H may form friedel salt which may also enhance the Anti-penetration capability of concrete.
文摘为了防止和减少隧道渗漏水病害,通过分析复合式衬砌隧道防排水的现状和存在的主要问题,研究隧道排水量和水压力控制值分级、上下分离的防排水体系、围岩防水能力、防水层和二次衬砌混凝土整体防水效果检验评价等,并对防排水系统的设计和参数选择提出以下建议:1)对于采用复合式衬砌的隧道,如果能满足环境保护及使用功能要求,其全隧道排水量宜控制在1.0 m 3/(m·d)以内,二次衬砌背后承受的水压力最大宜控制在1.0 MPa以内;2)为了减少隧道渗漏水发生的概率,并保证隧道结构的稳定,可考虑将拱、墙防排水体系和仰拱防排水体系分开设置,拱部、侧墙部位的渗水直接排入侧沟,仰拱部位的水主要通过纵向中心排水盲管排出,当水压力高时,通过与中心排水盲管连通的横向排水管将水引入新增的侧沟,并通过在横向排水管出水口安装的阀门进行限量排放;3)通过地面隔离墙(咬和桩)、地面注浆、洞内注浆、旋喷、超前管棚、超前管幕、施作双层衬砌等措施,阻断和减小来水通道,提高地层强度和完整性,降低隧道涌水量和衬砌背后的水压力,并降低大量排水对运营和环境的不利影响。
