A PHYSICAL MODEL OF A GRAVITY WALL ON COMPACTED KHON KAEN LOESS

Abstract

This paper presents the testing of retaining walls on compacted Khon Kaen loess by using
physical models. Khon Kaen loess was compacted in a box with the size 100 × 100 × 100 cm to achieve a dry
density of 19 kN/cu.m, which was 90% of the maximum dry density of the modified method. Moreover, the
moisture content of this compacted Khon Kaen loess was 11.85%. The effective friction angle () and the
effective cohesion (c) of this compacted Khon Kaen loess, as compacted, was 27 degrees and 12 kPa,
respectively, using a direct shear test. The soil sample was compacted in five layers in the box, and the thickness
of each layer was 45 cm. The dry density of each layer was examined using the sand cone method. A gravity
wall 15 × 30 × 50 cm in size, was installed in the box to determine the stability of the retaining wall. An active
force was applied using a pneumatic jack. The weight plate was applied to the top of the retaining wall as a
vertical force. The horizontal and vertical movements were measured using LDVT. The passive force was
measured using EPC at distances of 7, 10, 20, 32 and 45 cm from the retaining wall. The physical model
indicates that passive force decreases with distance from the gravity wall. The physical modeling found that k1
is 0.4, and k2 is 0.5. The factor of safety against sliding and overturning should be larger than 1.5 and 2.5,
respectively.