Geotechnical investigation and testing — Testing of geotechnical structures — Part 4: Testing of piles: dynamic load testing
岩土工程勘察与测试 - 岩土工程结构试验 - 第4部分:桩的动载荷试验
发布日期:
2018-03-16
ISO 22477-4:2018规定了动荷载试验的执行规范,其中单桩承受轴向压缩动荷载。
ISO 22477-4:2018概述了根据EN1997-1:2004+A1:2013中描述的以下方法和程序确定桩阻力评估所需的测试方法:
a) 动态冲击测试?通过评估桩头应变、加速度和/或位移随时间的变化来确定桩抗压强度;
b) 打桩公式?根据打桩过程中的锤击数和锤击能量评估桩抗压强度;
c) 波动方程分析?通过桩、土壤和打桩设备的建模,根据锤击数评估桩的抗压强度;
d) 多击动态测试?通过一系列旨在产生不同水平桩头位移和速度的锤击来评估桩的抗压强度。
ISO 22477-4:2018适用于轴向受压的桩。
ISO 22477-4:2018适用于EN 1536、EN 12699和EN 14199中提到的所有桩型。
本文件中考虑的试验仅限于桩的动荷载试验。
注1 ISO 22477-4可与EN1997结合使用-
1:2004+1:2013。EN 1997?1中提供了设计中要考虑的桩荷载试验极限状态分项系数的数值。对于EN 1997?1的设计,动载荷试验的结果将被视为与经过适当分析后测得的抗压强度Rc,m相等。
注2:附录A、B、D、E和F中给出了动态载荷试验结果分析程序的指南。
ISO 22477-4:2018提供了以下规范:
i) 调查试验,其中牺牲桩被加载至极限状态;
ii)控制试验,使桩承受超过正常使用极限状态的规定荷载。
注3:一般而言,调查测试侧重于桩型的一般知识;对照试验的重点是桩的一种特定应用。
ISO 22477-4:2018 establishes the specifications for the execution of dynamic load tests in which a single pile is subject to an axial dynamic load in compression.
ISO 22477-4:2018 outlines the methods of testing required to allow assessment of pile resistance to be determined from the following methods and procedures described in EN1997-1:2004+A1:2013:
a) dynamic impact testing?determination of pile compressive resistance by evaluation of measurements of strain and acceleration and or displacement at the pile head with respect to time;
b) pile driving formulae?evaluation of pile compressive resistance from blow counts and hammer energy during pile driving;
c) wave equation analysis?evaluation of pile compressive resistance from blow counts by modelling of the pile, soil and driving equipment;
d) multi-blow dynamic testing?evaluation of pile compressive resistance from a series of blows designed to generate different levels of pile head displacement and velocity.
ISO 22477-4:2018 is applicable to piles loaded axially in compression.
ISO 22477-4:2018 is applicable to all pile types mentioned in EN 1536, EN 12699 and EN 14199.
The tests considered in this document are limited to dynamic load tests on piles only.
NOTE 1 ISO 22477?4 can be used in conjunction with EN1997-1:2004+A1:2013. Numerical values of partial factors for limit states from pile load tests to be taken into account in design are provided in EN 1997?1. For design to EN 1997?1 the results from dynamic load tests will be considered equivalent to the measured compressive resistance Rc,m after being subject to appropriate analysis.
NOTE 2 Guidance on analysis procedures for dynamic load testing results is given in Annexes A, B, D, E and F.
ISO 22477-4:2018 provides specifications for:
i) investigation tests, whereby a sacrificial pile is loaded up to ultimate limit state;
ii) control tests, whereby the pile is loaded up to a specified load in excess of the serviceability limit state.
NOTE 3 Generally, an investigation test focuses on general knowledge of a pile type; a control test focuses on one specific application of a pile.