STABILITY AND DEFORMATION ANALYSIS OF BACK TO BACK MSE WALL (BBMSE WALL): CASE STUDY OF YOGYA-BAWEN ELEVATED TOLL SECTION I

• Main Author: Hanjani, Antania
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/74818
• Institution: Institut Teknologi Bandung

Anticipating the vulnerability of infrastructure due to earthquakes in Indonesia, it is very important for a structure to have an earthquake-resistant response. Public infrastructure is generally designed with a high risk category because the collapse of the structure has the potential to cause many fatalities. One example of the application of earthquake resistant structures is the use of BBMSE Wall (Back to Back Mechanically Stabilized Earth Wall) for elevated structure which can anticipate large deformations due to earthquake loadings. This final project discusses the design and analysis of deformation and stability of BBMSE Wall section I elevated 2 Yogya-Bawen Toll Road project. BBMSE WALL with a 32 m wide built with a 13 m high embankment. Soil investigations carried out by KSO Cipta Strada CS showed that there is a thick layer of sand with the potential for liquefaction to occur, so soil improvement using the Deep Soil Mixing is required before construction. The design and analysis of deformation and stability of the BBMSE Wall begins with checking the potential of liquefaction. After a clear indication of a liquefied soil, soil improvement is carried out using Deep Soil Mixing. The BBMSE Wall is then analyzed using pseudo static and dynamic loadings in PLAXIS. Pseudostatic modeling is carried out by applying loads behind the wall with the Mononobe- Okabe and Seed & Whitman loading. In addition, pseudo static load modeling is also done using the PLAXIS model condition. After pseudo static modeling, dynamic modeling is also carried out by first calibrating the ground motion from the bedrock to the surface. The values from each analysis are then compared and the effect of reinforcement length, reinforcement strength, and embankment properties is seen. Based on the results of the parametric study, it is found that the safety factor increased linearly with increasing reinforcement length, reinforcement strength, and soil cohesion values. In addition, with the same input parameters, pseudostatic loading using the Seed & Whitman provides the largest relative displacement compared to the other three loading models. Based on the analysis carried out, the recommended BBMSE Wall design for this final project is the use of steel strip with a minimum EA value of 4000 kN/m (medium strength) and a continuous reinforcement length of 32 m. The recommended vertical spacing between reinforcement is 0.5 m and the recommended embankment material is sand with cohession value c=10 ????????/????2.