Abstract：Landsonar，the technique of continuous profiling with an extremely elastic reflection wave of extremely small offset and a very wide frequency band，has following merits in checking thick lining made of reinforced concrete：(1) It is one of elastic wave reflect methods. Elastic wave will not be absorbed and shielded by the bar mat as radar wave. (2) This method can use a very wide frequency band of reflection wave induced by hammer source，and the wave-time curves of stations in a line can form a time-profile，and by analyzing frequency spectrum，phase and amplitude of reflection wave and superposition of waves，the following can be determined or detected：the thickness of lining，the cavities and empty areas behind the lining，the position of low density in concrete. The liability of landsonar in checking thick lining is proved by practice in this paper.
钟世航. 大型地下洞室衬砌质量及背后空区的一种检测技术[J]. 岩石力学与工程学报, 2004, 23(S2): 5181-5183.
Zhong Shihang. Technique for Checking of Lining Quality and Empty Areas behind The Lining of Big Underground CAVERN. , 2004, 23(S2): 5181-5183.
2004, Vol. 23 
