摘要
预应力钢筒混凝土输水管线(PCCP)已广泛应用于地下输水工程,特别是南水北调工程。管道接口属于半刚性结构,相邻管道可产生一定的自由转角,在自由转角范围内两管之间不会产生内力。当相对转角大于自由转角时,两管会产生相互作用力,作用力过大会导致PCCP管的破坏,如何有效地控制不均匀软土地基上相邻管道转角成为研究管道安全的关键问题之一。首先分析了导致PCCP管线产生相对转角的机制,结合现场试验和数值分析对控制PCCP管线相对转角的关键因素进行研究。研究表明,相对转角的敏感因素为管道底部碎石垫层厚度、腰部以下砂垫层(砂包角)厚度和压实度,随着碎石垫层厚度增大、砂垫层(砂包角)厚度和压实度增加,管线相对转角降低,通过控制这3个因素可有效控制PCCP管的相对转角。研究成果可为软土地基上PCCP输水工程设计提供依据和指导。
The prestressed concrete cylinder pipe(PCCP) has been widely used in underground water conveyance projects, especially in the south-to-north water diversion project. Pipeline interface belongs to the semi-rigid structure; while the relative angle of adjacent PCCP is larger than the allowable angle, PCCP will produces internal force in bell and spigot. However, if it is located in the serious uneven soft soil foundation, it may produce excessive angle and even destroyed. Therefore, how to control the PCCP produce excessive angle in soft soil foundation becomes one of the key issues in researching pipeline safety. Firstly, what factors lead to relative angle is analyzed. Then combined with field test and numerical analysis, the key factors for control PCCP angle is determined. Research results show that the thickness of the gravel cushion, the thickness and compactness of the sand cushion are the most important factors to control excessive angle. As the thickness of the gravel cushion, the thickness and compactness of the sand cushion increase, the relative angles decrease. The research results can provide basis and guidance for PCCP pipeline engineering design in soft soil foundations.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2015年第S1期293-298,共6页
Rock and Soil Mechanics
基金
国家自然科学基金(No.41402263)
天津市自然科学基金重点项目(No.13JCZDJC35300)
教育部新教师基金(No.20130032120053)
关键词
软土地基
预应力钢筒混凝土管(PCCP)
自由转角
施工工艺
soft soil foundation
prestressed concrete cylinder pipe(PCCP)
allowable angle
construction technology
