Experimental Research and Numerical Simulation on Grouting Quality of Shield Tunnel Based on Impact Echo Method

Table 6

Comparison of peak frequency between test results and finite element simulation under different working conditions.

Model number	(Hz)	(Hz)	(Hz)
SG-A-DE	6738 6104 10.4%	4590 5127 −10.5%	Not obvious not obvious
SG-A-ND	6348 6104 4.0%	—	3042 2930 3.8%
SG-B-DE	6543 6104 7.2%	4883 4639 5.3%	Not obvious 3418
SG-B-ND	6640 6348 4.6%	—	3571 3662 −2.5%
SG-C-DE	6641 6348 4.6%	5566 4883 13.9%	Not obvious 3662
SG-C-ND	6641 6104 8.8%	—	4199 4639 −9.5%

Note: content in [ ] is finite element simulation results; content in bold is percentage difference between tested results and finite element simulated results.