Open AccessUCS field estimation of intact rock using the Schmidt hammer: A new empirical approach
Author(s) -
Alberto Bolla,
Paolo Paronuzzi
Publication year - 2021
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.179
H-Index - 26
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/833/1/012014
Subject(s) - schmidt hammer , marl , geology , lithology , hammer , rhyolite , outcrop , mineralogy , geotechnical engineering , mathematics , compressive strength , engineering , seismology , geomorphology , geochemistry , structural engineering , structural basin , physics , thermodynamics , volcano , volcanic rock
In the present work we discuss the results of a number of Schmidt hammer tests (total number of impacts N > 2,400) that were performed in situ on rock outcrops of different lithology (marl, calcareous marl, limestone, sandstone, quartz sandstone and rhyolite) that occur in Italy. Firstly, a specific field procedure to choose the reference value of the rebound index adopted to calculate UCS of intact rock is suggested. A relationship between L and N hammer rebound index values (R L and R N , respectively) is subsequently assessed. Considering the experimental datasets provided by a Schmidt hammer construction company and other research available in literature, a new exponential equation for the correlation between R L and UCS of intact rock has been derived. Considering the here-proposed R L -R N relationship, a new exponential correlation between R N and UCS has also been defined. The newly proposed procedure and relationships were successfully utilised to determine the intact rock strength of different rocks. The calculated UCS values are very similar when using both types of Schmidt hammer (L and N) and are generally in line with previous determinations from experimental data available in literature.