Multichannel analysis of the surface waves of earth materials in some parts of Lagos State, Nigeria

• Main Authors: Adegbola R.B., Oyedele K.F., Adeoti L., Adeloye A.B.
• Format: Article
• Language: English
• Published: Sciendo 2016-09-01
• Series: Materials and Geoenvironment
• Subjects: multichannel analysis of surface waves (masw); weakening of structures; rigidity modulus; standard penetration test (spt); n-value; subsidence
• Online Access: https://doi.org/10.1515/rmzmag-2016-0007

We present a method that utilizes multichannel analysis of surface waves (MASW), which was used to measure shear wave velocities, with a view to establishing the probable causes of road failure, subsidence and weakening of structures in some local government areas in Lagos, Nigeria. MASW data were acquired using a 24-channel seismograph. The acquired data were processed and transformed into a two-dimensional (2-D) structure reflective of the depth and surface wave velocity distribution within a depth of 0–15 m beneath the surface using SURFSEIS software. The shear wave velocity data were compared with other geophysical/ borehole data that were acquired along the same profile. The comparison and correlation illustrate the accuracy and consistency of MASW-derived shear wave velocity profiles. Rigidity modulus and N-value were also generated. The study showed that the low velocity/ very low velocity data are reflective of organic clay/ peat materials and thus likely responsible for the failure, subsidence and weakening of structures within the study areas.