在澜沧江小湾水电站拱坝建基面进行了5个钻孔的基 岩钻孔弹模测试，以评价开挖爆破对岩体的松弛效应与卸荷深度。扼要介绍了钻孔弹模测试 原理及测试结果，估计了卸荷松弛深度, 并与单孔声波监测结果进行了对比分析。   

Borehole elasticity modulus measurements were conduct ed in five holes drilled from the excavated rock foundation surface of Xiaowan H ydropower Stations arch dam, situated on Lancang River, in order to evaluate t he unloading relaxation depth due to excavation blasting. The principle of boreh ole elasticity modulus measurement and results are presented, and the unloading relaxation depth is estimated. The depth is compared with that obtained by singl e -hole sonic velocity monitoring.