Study on condition assessment of embankments settled in peaty ground by using geophysical exploration

¹ Civil Engineering Research Institute for Cold Region, Sapporo, Japan
² Public Works Research Institute, Tsukuba, Japan

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

In Hokkaido, peaty ground is widely distributed, and it’s estimated that there’s a considerable amount of road embankment constructed and used on such ground. Peaty ground have extremely low undrained shear strength and high compressibility. When embankments are constructed on peaty ground that have been improved by surcharge method, accelerated consolidation method, the embankments are settled in the peaty ground over time, and a part of the embankment that’s settled below the groundwater level becomes saturated. When road embankments made of liquefiable embankment materials such as sandy soil are subjected to seismic motion, the embankment itself liquefies, leading to major collapse. Therefore, it’s important to determine the distribution and thickness of saturated embankments continuously and extensively from the viewpoint of maintenance and management of road embankments. Therefore, in this study, we conducted geophysical surveys with the aim of obtaining distribution of ground conditions simply and continuously. The results of the comparison and verification between geophysical surveys and conventional ground investigation methods are described, as it was found that the boundary between the bottom of the clay embankment and the top of the peat layer could be evaluated by supplementing the point information.