Optimalisasi biaya konstruksi pondasi RISHA melalui analisis perbandingan metode precast dan cast-in-situ

This study examines cost optimization strategies for RISHA (Simple Healthy Instant House) foundation construction through a comparative analysis of precast and cast-in-place methods. RISHA is an innovative modular housing technology developed by the Ministry of Public Works and Housing in 2004, equipped with a knock-down system and dry joints designed for earthquake resistance. This study uses a parallel comparison method to analyze three types of precast foundation pocket, foundation blocks, and knock-down—against conventional cast-in-place foundations under identical geotechnical conditions. The analysis includes geotechnical assessment using CPT tests, structural evaluation of load capacity ranging from 958-2406 kg per foundation point, and comprehensive cost estimates based on PERMEN PUPR No. 8/2023 guidelines. The results show that precast foundation systems, particularly the knock-down and block footing variants, achieve significant cost savings of up to IDR 1.1 million per housing unit compared to conventional methods, while maintaining structural integrity and meeting load capacity requirements in soft soil conditions. The knock-down system demonstrates superior advantages in large-scale RISHA projects by reducing production, installation, and connection costs. All types of foundations successfully support the load of RISHA panels and ensure shear stability. This study recommends the application of a precast knock-down foundation system for large-scale RISHA projects to optimize construction costs while maintaining geotechnical quality standards and accelerating installation time.