Известия Томского политехнического университета: Инжиниринг георесурсов (Aug 2017)
Opportunities of ground penetrating radar at searching supporting walls and enclosing constructions
Abstract
Relevance of the research is caused by the necessity to solve engineering geological tasks in non-destructive investigation of solidity and technical conditions of supporting walls, erected in potentially landslide dangerous areas, by express geophysical methods. The aim of the research is to estimate the informational content of the ground penetrating radar method in engineering and construction area at survey of vertical supporting wall with following processing of field observations by specialized programmes GEORADAR-ECSPERT and ATRAN. The paper highlights the limited mobility of the ultrasound and acoustic methods in which the intimate contact of transmitting and receiving sensors of seismic wave field with vertical surface of the studied object is required when measuring. This does not technically allow recording field signal in motion. Methods of the study: ground penetrating radar survey of supporting wall by radar OKO with 400 MGz antenna unit by means of moving of the latter along vertical profiles on specially installed rope skis pressing the unit to the wall with help of the wooden pole at registration and control of radargram in online mode. Results. The paper demonstrates the opportunities of the attributive analysis of the ground penetrating radar survey data for studying the conditions of supporting wall on landslide slope of the right bank of the Don river in Rostov-on-Don with detection and contouring by the Q-favtor attribute values the areas with relatively solid and relatively weak masonry and location of metal dowels (steel pipes) into the front and side walls body. The diagrams were interpreted on the base of the diffracted wave pattern studying method and distinctive «ringing» in the shape of re-reflections from dotted objects. Additionally the authors have analysed the reflected signals energy in the program ATRAN. In outcome of the studies the contact of the wall with ground was explored. It can be considered relatively evenly dense. For the side wall the lower part is denser than the upper one, and for the front wall the less dense contact into range of 20-25 m from the left edge of the wall is observed.
