Physical and Mechanical Properties of Beachrocks in Okinawa Island

Abstract

 There are very few reports about physical and mechanical properties of beachrocks in the world. To obtain the properties of beachrocks and to investigate their correlations between unconfined compression strength and other properties such as density, water content, etc., we performed a series of in-situ tests and laboratory tests for beachrocks in Okinawa Island. As a result, it was shown that the average values of unconfined compression strengths of the beachrock samples obtained from three testing sites were 11.14MPa, 19.91MPa and 42.23MPa, respectively. It was also understood that density and unconfined compression strength of the beachrocks increased along with the passage of time while water content decreased. Moreover, it was found that there was a relationship like q_u = 0.00000654 t²+0.0101 t between unconfined compression strength, q_u (MPa), and calibrated radiocarbon age, t(y Cal BP).