Static and Seismic Stability of the Largest Malaysian Sanitary Landfill

• Main Author: Saiedi, Hamed
• Format: Final Year Project
• Language: English
• Published: Universiti Teknologi PETRONAS 2008
• Subjects: TA Engineering (General). Civil engineering (General)
• Online Access: http://utpedia.utp.edu.my/10009/1/2008%20Bachelor%20-%20Static%20And%20Seismic%20Stability%20Of%20The%20Largest%20Malaysian%20Sanitary%20Landfill.pdf; http://utpedia.utp.edu.my/10009/

In light of the huge landfill failures in South-East Asia in the past 10 years, namely failures of the Payatas and Leuwigajah landfills in 2000 and 2005 respectively, the necessity of assessing the stability of Malaysian landfills is signified. This project aims to investigate the static and seismic stability of the Bukit Tagar Sanitary Landfill, the largest Malaysian sanitary landfill, serving 8 million people with a design capacity of 120million m3 to operate for 40 years. This study can be very insightful in identifying the extent to which geotechnical and hydrological parameters and earthquakes can affect the stability of landfills in Malaysia. Most significantly, the objective is to assess how susceptible Malaysian landfills are to stability failures under both static and seismic conditions. Numerous field investigations were conducted indicating proper incorporation of stability enhancing practices in Malaysian sanitary landfills. Static and seismic stability of the landfill were simulated using the geotechnical software, GeoStudio. Sensitivity analysis was carried out to study the effects of water level and waste's unit weight and shear strength parameters (i.e. friction angle and cohesion) on the stability of the Bukit Tagar landfill. These analyses indicated an adequate stability design of the landfill. However, inadequate drainage together with heavy precipitations may lead to stability failures. Generally, landfill stability is sensitive to water levels to a very large extent, to waste unit weight to a fair extent and to waste shear strength to a lesser extent. This signifies the vitality of good drainage and best compaction practices for the waste to increase landfill stability. Frequency analysis indicated that an earthquake with a return period of 100 years in Malaysia would be of a local mag1_1itude of7.99. Seismic stability simulations using the equivalent-linear dynamic analysis showed that Bukit Tagar landfill had an acceptable stability design in drained and likely undrained conditions against this 7.99 magnitude earthquake. The necessity of proper drainage for stability of the landfill is highlighted once more by the critical FS values encountered for the undrained condition in the seismic analysis. Keywords: Landfill stability, Earthquake, South East Asia, Malaysian landfill, Bukit Tagar landfill, Municipal Waste