【Haichuan Chemical Construction Technology】When controlling the parameters for driving precast piles, should elevation or penetration depth be used?

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This post was last edited by HaiChuan LaoYu on 2026-5-7 at 22:29. Learn about construction techniques to build chemical engineering projects successfully. [HaiChuan Chemical Construction Techniques] – continuously updated compilation thread: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=5719396 -------------------------------------------------------------------------------- I. Core control principles: When constructing precast piles, the selection of control parameters regarding penetration depth and elevation is based on the properties of the soil in the bearing layer at the pile tip; the core principle is to adopt a dynamic dual-control approach that combines primary and secondary controls. Memory tip: For soft soil, consider depth; for hard soil, consider penetration. II. Detailed Operating Procedures 1. Control primarily based on elevation (with the pile tip located in ordinary soil layers). Control objective: Piling should be stopped once the designed elevation of the pile tip is reached; penetration depth serves as an important reference indicator. If the penetration value is abnormally high when approaching the designed elevation, it may indicate the presence of weak interlayers beneath the pile tip; in such cases, the analysis should be suspended. Relevant standards: Article 7.4.6, Paragraph 1 of JGJ 94-2008, \"Technical Standards for Prestressed Concrete Pipe Piles\", and Article 8.1.12, Point 2 of JGJ/T 406-2017. Control is primarily based on penetration value (with the pile tip reaching hard soil layers); the primary termination condition for driving the pile is achieving the penetration value specified in the design requirements. The elevation value serves as an auxiliary reference indicator. While ensuring compliance with the penetration requirements, the elevation should be brought as close as possible to the specified value. The relevant standards are as follows: JGJ 94-2008, Article 7.4.6, Paragraph 2, Item 3 – Handling of special cases: When the penetration requirement is met but the elevation requirement is not. This is the situation that most often gives rise to disputes during construction, and the standards provide clear procedures for dealing with it: 1. Continue hammering: Hammering should continue for 3 sets, with 10 blows per set. 2. Criteria for determination: Measure the penetration after these 3 sets of blows; if the penetration for each set of 10 blows does not exceed the value specified in the standards, then it can be confirmed that hammering can be stopped. 3. Relevant standards: JGJ 94-2008, Article 7.4.6, Paragraph 3; GB 51004-2015, Article 5.5.24, Paragraph 2. 4. Control characteristics of static pile driving: In normal soil layers, the elevation is the primary consideration, with pile driving force playing a secondary role; in hard soil layers, pile driving force is the primary factor, with elevation being secondary. Relevant standard: GB 51004-2015, Article 5.5.25