On the ground foundation works for Bldg site, Rock classification test can be obtained as follows due to the International Society for Rock Mechanics. 1. In-take test ; Compression strength, Point load test. 2. In-situ test : Schmidt hammer test. Burden test finaly the convinient co-relation table between strength and S.H. test were carried out for site-engineer. This project is one of contineous works regarding to Burden test from Jack leg drill( ø 36mm) to Crawler drill( ø 75mm) use.