预制混凝土支护管桩在深基坑工程中的应用
Application of precast concrete pipe piles in a deep excavation project
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摘要: 先张法预应力预制混凝土支护管桩作为一种新型的基坑支护桩,具有桩身质量好、强度高和成桩可靠等特点值得推广与应用。基于基坑位移计算方法,分析了采用预应力预制混凝土支护管桩进行基坑支护,影响其位移变化的参数,并结合南京邮电大学科研综合楼基坑工程实例,介绍了支护桩的布置方式,对比了基坑位移的理论计算值与实测值,结果表明:计算位移变化平缓,最大值约在17.0~23.2 mm之间;现场实测的最大水平位移值在16.10~21.50 mm之间,二者数值接近,变化规律基本一致,证实了预应力预制混凝土支护管桩用于基坑支护的可靠性和有效性,值得在同类工程中参考。Abstract: As a new type of retaining pile for foundation pit engineering, the pre-tensioned prestressed concrete pipe pile has many advantages, such as a good pile quality, high strength and reliable construction quality. It is worthy of popularization and application. Based on the displacement calculation method, the parameters that affect the displacement of excavation are further analyzed when the prestressed concrete pipe pile is used as the retaining pile. Through a practical example of research building of NUPT, the layout of retaining piles is introduced, and the measured displacement of the foundation pit is compared with the theoretical results. It is shown that the calculated displacement changes gently, and the maximum varies from 17.0 mm to 23.2 mm; while the measured values are between 16.1mm and 21.5mm. They are consistent with each other, and the change rule is almost identical. Thus the reliability and validity of the prestressed concrete retaining pipe pile are conformed. It may provide a good reference for similar projects..