Case Study: In Situ Experimental Investigation on Overburden Consolidation Grouting for Columnar Jointed Basalt Dam Foundation

Table 8

Variation in wave velocity before and after grouting.

Before/after grouting	Velocity range (m/s)	Average minimum (m/s)	Average maximum (m/s)	Average velocity (m/s)	Statistical points
Before	3333~5970	4528	5269	4980	2105
After	3448~6061	4889	5491	5345	1253