Abstract: According to the project construction of Xiang'an undersea tunnel, numerical simulation on loosen zone of surrounding rock after blasting was conducted by using FLAC3D software. And the ultrasonic wave method was applied to measure the loosening zone of representative A1 tenders F4 weathering groove. By the contrast and analysis, it is indicated that the numerical results and the test results are consistent. The research results provided a basis and guide for determining the support parameters for loosening zone of surrounding rock.

Key words: Tunnel blasting, Loosening zone, Numerical simulation, Test analysis