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Site investigation
Published in Burt G. Look, Earthworks, 2023
Figures 2.4-9 compares the supervisor’s blow count with digital measurements. In this case, driving to refusal occurred in 42 seconds with an automatic trip hammer. The experienced supervisor measured 30 blows at 40 mm for refusal while the digital measurements showed 30 blows occurred at 48 mm. This is a 20% counting error.
Determination of the penetration energy in the Standard Penetration Test
Published in Frans B.J. Barends, Application of Stress-Wave Theory to Piles, 2022
H.J. van der Graaf, M.H.J.P. van den Heuvel
At first, a range of calibration tests is carried out at groundlevel to determine the influence of the drop height and the efficiency of the apparatus itself. The device contains no rods when used at groundlevel, so M2 contains only the weight of the anvil and amounts to 24.35 kg. The weight of the used trip hammer is 64.6 kg.
Site exploration
Published in Rodrigo Salgado, The Engineering of Foundations, Slopes and Retaining Structures, 2022
Stroud (1975) based his correlations on relatively insensitive clays (with sensitivity <3). He also mentions that an automatic trip hammer was used. According to Clayton (1990), the average energy ratio for this type of hammer used in the United Kingdom is 73%. So, using N60, the correlation Equations (7.9) and (7.10) would become: supA=0.82f1N60mvpA=1.21f2N60
Study on geotechnical characteristics of marine soil at Hong Kong–Zhuhai–Macao tunnel
Published in Marine Georesources & Geotechnology, 2020
Xiabing Yue, Yongli Xie, Hongguang Zhang, Yapeng Niu, Shasha Zhang, Jing Li
SPTs were performed using an automatic trip hammer and standard sampler equipment; the free drop distance of the hammer equaled 63.5 kg and 76 cm, respectively. SPTs were generally conducted every 1.5–2.0 m. Using a rod with a diameter equal to 42 mm, each SPT test hole was made using the free hammering method of automatic decoupling. The hammering rate was less than 30 kN/min. First, we penetrated 15 cm into soils without recording the number of hammers, and then penetration continued. The number of hammers per 7.5 cm was recorded, upon penetrating an additional 30 cm into soils, the number of hammers was taken as the standard penetration test N value. If the number of hammers exceeded 50 and the penetration depth was less than 30 cm, the test was terminated. SPT tests were conducted in accordance with Chinese standard.
Metal Ties in Genoa, Italy: Manufacture, Trade, and Use from the 15th to the 18th Century
Published in International Journal of Architectural Heritage, 2019
The minimum equipment of an ironworks consisted of a furnace, the ventilation systems connected to it (bellows or, from the 17th century, trompes, as reported in Calegari 1977, 23–24, Baraldi 2001, 205) and a trip hammer operated by a water wheel, hammer which, in the 15th century, became heavier (Baraldi 2005, 164). All authors agree that the product of the first stage of hammering (“purged iron,” Baraldi 1984) was the so-called quarone, a thick iron bar obtained by beating, subdivision into two pyramid-shaped pieces (tronchéij), heating and re-beating of the mass of metal (massé) extracted from the reduction furnace, as described in the memoirs of a witness, Luigi Bazzano, collected in a manuscript from 1923 (Baraldi 1979). According to Bazzano, the quaròn had a square section of 6 cm on each side (ibidem, 179), slightly less than but comparable to that of the thicker 17th-century bars “in bundles.”
Prediction of standard penetration test N-value from dynamic probing light N-value using ANFIS and multiple regression models
Published in International Journal of Geotechnical Engineering, 2021
Mohammadjavad Arabpour Roghabadi, Mehdi Momeni, Zahra Zangenehmadar
The SPT equipment consisted of a standard sampler and a 63.5 kg automatic trip hammer with a drop height of 760 mm capable of averagely delivering 70% of the theoretical energy as measured during equipment calibration by the manufacturer. The DPL equipment consisted of a 10 kg hammer with a falling height of 500 mm. The rods are 22 mm in diameter and are fitted to a 25.2 mm diameter cone of 90° apex angle.