MECHANICAL BEHAVIOR OF GABIONS UNDER SHEAR AND COMPRESSION

Abstract

Retaining structures now a days become so important that need of a good quality material for construction of the structures is very high. Forces of nature affect these structures severely hence the material should be so adequate to withstand against these conditions. i'here are so many materials used for the construction or methods used to improve the quality of construction. Gabion is one of the materials developed in recent time and used for many construction works. Being a flexible structure gabion can withstand against large deformations and gives us prior warning before failure. Gabions are used for construction so frequently it becomes a necessity to understand the behavior of gabion subjected to loading. 'l'his reports aims to study the behavior of the gabion material when subjected to shear and compressive load under different conditions. The investigation was carried out on servo controlled large direct shear machine. The shear tests were conducted on stones with gabion and stones without gabion samples to examine the difference in behavior of both the samples under shear. Sand stone was used in shear and basalt was used in compression tests as a filler stones of size 150 mm-250 mm (1.5-2.5 times the mesh opening size) and 10 crnx12 cm gabion of wire diameter 2.7 mm having vertical orientation of mesh was used. A shear box 750mm in width, 750 mm in length and 1000mm in height was used for shear test. These tests were performed at different normal pressures i.e. 80kPa, 100kPa, 150kPa and 200kPa under constant strain rate i.e. 0.4mm/mm. Load vs. shear displacement and stress vs. percentage shear displacement curves were plotted and finally strength parameters were carried out from normal stress vs. shear stress plot. The compression testing were performed on gabion of size lmxlmxlm under two different conditions i.e. unrestricted lateral expansion and restricted lateral expansion from 3 sides in order to examine the response of gabion under similar conditions from which gabion are subjected inside a retaining structure. Load corresponding to deformation were plotted and peak load and max deformation before failure was observed.