1.0.1 In order to strengthen the management of testing of railway piles, improve the level of testing technology, unify testing methods and results documentation, this Specification is formulated to provide reliable basis for both the design and construction acceptance and ensure engineering quality.
1. 0. 2 This Specification is applicable to the testing and the assessment of pile integrity and bearing capacity of railway piles.
1. 0. 3 Testing methods of foundation piles shall be reasonably selected according to geological conditions, types of foundation piles, dimensions, features and the scope of application of all kinds of testing method. They shall be safe, applicable, economic and reasonable, with exact data and advanced technology.
1. 0. 4 The testing institution shall be certified by administrative department in charge of measurement at provincial level or above and have a testing certificate of special items issued by this department. The testing staff shall be trained, examined and start the work with a certificate of relevant testing method.
1. 0. 5 Besides this Specification, the testing of railway piles shall also conform to relevant national current mandatory standards.
2 Terms and Symbols
2.1 Terms
2. 1. 1 "Foundation pile" means single pile in the pile foundation.
2. 1.2 "Pile integrity" is a comprehensive qualitative index, reflecting relative change of section size of the pile and material denseness & continuity of the pile.
2.1.3 "Pile defects" are ruptures, cracks, necking, infiltrated mud, segregation, cavity, honeycomb and surface loosening existing in the pile.
2. 1. 4 "Low Strain Reflected Wave Method" is a testing method for the determination of pile integrity, using the transient excitation of low energy to apply impact load to the pile top, field measuring the acceleration (or speed) time-history curve and analyzing time domain and frequency domain of wave theory.
2. 1. 5 "Crosshole Sonic Logging" is a testing method for the determination of pile integrity in accordance with relative change of such acoustic parameters as sonic time, frequency and amplitude attenuation when actual measured sound wave transmitted in the concrete media, shooting and receiving sound waves among pre-buried sonic-testing tubes of the pile.
2.1.6 "High strain dynamic testing" is a testing method for the determination of pile integrity and vertical compression bearing capacity of single pile, applying impact load of high energy to the pile top, field measuring the speed and force time curve by employing wave theory.
2. 1. 7 "Static loading test" is a testing method for the determination of relevant vertical compression bearing capacity, vertical uplift bearing capacity or horizontal bearing capacity of single pile by observation of settlement, uplift displacement and horizontal displacement happened with time at the pile top when vertical pressure, vertical uplift force and horizontal thrust applied to the pile top stepwise.
2. 1. 8 "Core drilling method" is a testing method for the determination of pile integrity and characters of rock and soil at the pile base when a drilling rig drills and takes concrete on the pile and core sample of bearing stratum at the pile base.
