## 1 Introduction  
In recent decades, with rapid urban population growth, underground constructions which extend human activities into underground spaces have attracted increasing attention [1; 2]. A metro system is a kind of underground construction in an urban region to perfect alternative transportation in order to overcome traffic congestion, road accidents and environmental pollution caused by vehicles in the modern international metropolis [2; 3]. A metro project faces significant challenges of construction for the complex conditions, e.g., soft soil layers, interaction caused by the urban infrastructures, vibration issues, accidents during the construction phase, etc. Thus, the safety level and durability of metro construction are of critical importance [4]. The constant need to improve the operational safety of construction has driven the development of non-destructive evaluation techniques and in-site monitoring methods aimed at the ongoing assessment of the metro rail corridors and near-surface soil layers [5; 6]. The most important step of the underground construction in geotechnical evaluation is in situ identification of soil properties. The soil is a kind of multiphase, particulate medium with complex mechanical profiles. The analysis of wave propagation is an essential tool for the identification of the elastic and dissipative characteristics of soil layers in dynamic conditions. The mechanical properties of the soil are obtained by analyzing dynamic problems as important parameters for site response evaluation, vibration control, earthquake engineering, etc. [3; 7]. The compressional and shear waves propagating in the subsoil has been widely used for the evaluation for various purposes with a great number of techniques: seismic reflection and refraction technique, downhole testing, seismic tomography, surface wave detection technique and so on [8]. In recent decades, as a non-destructive in situ evaluation technique, the surface wave method has been attracting increasing attention from both geophysicists and geotechnical engineers. In the 1960s, after being introduced by seismologists, [PERSON] [9] developed a prototype for the surface wave measurement system. Multiple stations were employed to estimate the characterizations of the subsurface of the Earth. [PERSON] and [PERSON] [10] studied the surface wave technique for the evaluation of the dynamic parameters of the subsoil. [PERSON] et al. [8] discussed the applications of various wave modes (Rayleigh wave, Stoneley wave, and Love wave) for real engineering problems. Because of the complex mechanical properties of the subsoil, the shallow shear wave velocity is a function witnessed from the characteristics of the soil layers and the frequency of ground motion. To obtain the wave velocity map, an on-site surface wave method has been proposed to involve multiple geophones to acquire the ground motion signals for the benefit of non-intrusive testing, effectiveness, and reliable data. The multiple channel data will be analyzed by interpretation algorithms (such as, the two-receiver spectral analysis of surface wave (SASW) method [11] and the multichannel analysis of surface waves (MASW) method [12; 13], etc.) to achieve an experimental multimode dispersive image. In spite of the demonstration of accurate, high-resolution dispersion image, the application of a large number of geophones becomes a bottleneck to widespread use of the technique from the laboratory to large scalar engineering applications. Thus, in order to reduce the redundant geophones used in conventional measurements, this paper contributes to this objective by exploring a novel in-site technique based on compressive sensing (CS) to reduce the number of required geophone and measurements for the estimation of surface wave velocity of the subsoil. CS has been applied to recover the multimodal and dispersive properties of Lamb wave from observed data in the laboratory for analysis, reconstruction, and prediction of guided waves [14; 15; 16; 17; 18; 19; 20]. [PERSON] et al.