THE PERFORMANCE OF BAMBOO MAT WITH PILES AS REINFORCEMENT OF PEAT SOIL

Abstract

Peat soil is classified as problematic soil when used as a subgrade. The bearing capacity of this soil is generally very low, including a low CBR (California Bearing Ratio) value, settlement, and relatively high water content. This soil is not sufficiently reinforced, so it requires an embankment as a subgrade of stabilized soil to achieve a sufficiently high CBR value. This study aims to evaluate the performance of a bamboo mat reinforcement system, combined with reinforced piles and a subgrade of marble ash stabilized soil. The study began by testing the interaction between the peat soil and the reinforcement material, followed by observations from a series of CBR tests that measured load-penetration relationships in a test box placed on subgrades consisting of soil reinforced with piles and bamboo mats. Reinforcement piles are distinguished by their lengths of 20-50 cm as single piles and pile groups. Bamboo mats are placed between the peat soil surface and the subgrade. The subgrade is compacted in 10 cm and 20 cm increments. CBR tests are conducted on each reinforcement system scheme. The results showed that bamboo mat reinforcement increased the CBR value by 1.8 times, reinforced piles increased the CBR value by 1.2-1.5 times, and the combination of both increased the CBR value by 2.2-2.7 times compared to the reinforced soil. Long-term curing of the subgrade of clay soil with 6% marble ash had an impact on increasing the CBR value by 1.1-1.3 times compared to the short-term subgrade CBR value.