NAME: ADARNE, JAYMEE LOU E. DATE: SEPTEMBER 01, 2023 SUBJ/SEC: CE 401-CE31S7 MODULE 1 - ASSIGNMENT A. Case Study of Geotechnical Failure in the Philippines Paper documents failure at Payatas landfill in the Philippines that killed 330 : Location - Quezon City, Philippines This paper discusses an investigation into a slope failure that occurred at the Payatas landfill in Quezon City, Philippines, on July 10th, 2000, resulting in the tragic death of at least 330 people. The failure was triggered by two weeks of heavy rainfall from two typhoons. The authors conducted a detailed analysis of the factors that contributed to this slope failure. It describes a catastrophic slope failure event that took place at the Payatas landfill. This event was a significant tragedy, resulting in a high number of casualties. The paper identifies several factors that played a role in causing the slope failure: ● Raised Leachate Level: The level of leachate (liquid waste) within the landfill had risen, which likely affected the stability of the slope. ● Landfill Gas: Natural processes of aerobic and anaerobic degradation within the landfill produced landfill gas, which could have influenced the stability of the slope. ● Over-Steepened Slope: The landfill's slope had become excessively steep, contributing to its instability. This paper discusses an investigation into a slope failure that occurred at the Payatas landfill in Quezon City, Philippines, on July 10th, 2000, resulting in the tragic death of at least 330 people. The failure was triggered by two weeks of heavy rainfall from two typhoons. The authors conducted a detailed analysis of the factors that contributed to this slope failure. The findings and insights from this case study are used to make recommendations for the design and management of landfills in tropical areas. This is important for preventing similar disasters in the future. This case conducts slope stability analyses to better comprehend the mechanics of the failure. These analyses help in assessing how the combination of factors mentioned earlier contributed to the slope's instability. The authors identified the critical failure surface within the landfill. This is the specific location or layer within the landfill where the failure initiated. It provides a description of the geological and environmental conditions at the Payatas landfill. Understanding these conditions is crucial for assessing the factors leading to the slope failure. Also, The authors utilized the Hydrologic Evaluation of Landfill Performance (HELP) model to predict the leachate level within the waste at the time of the slope failure. This modeling approach helps in understanding how specific environmental factors contributed to the failure. In summary, this paper presents a comprehensive investigation into the slope failure at the Payatas landfill in the Philippines. It examines the various contributing factors, uses modelling to understand the dynamics involved, and provides recommendations for improving landfill management in tropical regions to prevent such tragedies in the future. Additionally, it acknowledges the uncertainties in the analysis, which is an essential aspect of any scientific study. Lessons Learned from this failures: ● The case of the Payatas landfill serves as a valuable lesson for other landfills in tropical regions. It highlights the importance of addressing specific environmental and geological challenges unique to these areas. Before establishing or expanding landfill sites, thorough environmental impact assessments are crucial. Understanding the geological and environmental conditions of an area is essential for assessing the potential risks associated with landfills. Also, Proper management of leachate, the liquid waste generated within landfills, is vital. Elevated leachate levels can weaken the structural integrity of landfill slopes and lead to disasters. ● The use of hydrological models like the Hydrologic Evaluation of Landfill Performance (HELP) model can help predict the behavior of landfill components, such as leachate levels, under various conditions. Such models aid in understanding and mitigating risks. ● Strict safety regulations and guidelines for landfill design, construction, and operation are essential. These regulations should consider the unique challenges of landfills in tropical areas with heavy rainfall.Communities living near landfills should be made aware of potential risks, and evacuation plans should be in place in case of emergencies. Recognizing and addressing uncertainty in engineering and environmental studies is crucial. It's essential to understand the limitations of analyses and models used in assessing risk. B. Case Study of Geotechnical Failure in the other countries Topography at the 3,300-acre site in Southern California consists of hilly terrain with jagged ridges and steep slopes; geology consists of folded and faulted sedimentary rocks : Location - Southern California One of the faults shows evidence of recent fault displacement. Earthquakes have been instrumentally located along the fault, the two most recent were a ML=2.4 and 4.6 occurred on September 3, 2002. Because of the recency of displacement and the presence of earthquakes along the fault, geologists classified it as being “active”. The fault was designated by the State to be in the Alquist-Priolo Special Studies Zone Act, before the initial sitespecific investigations were made. The site covers 3,300 acres and is characterized by hilly terrain with jagged ridges and steep slopes. This topographic profile indicates significant elevation changes and rugged landforms across the site. Such terrain can have a profound impact on land use, construction, and development planning. The hilly and steep nature of the landscape may require specialized engineering and construction techniques to ensure stability and safety when building infrastructure or structures on the site. Proper land use planning is essential to optimize the utilization of this terrain while minimizing environmental impacts. The geological composition of the site consists of folded and faulted sedimentary rocks. This indicates that the area has a complex geological history with tectonic forces leading to the folding and faulting of sedimentary rock layers. Understanding the geological characteristics is crucial for assessing the site's stability, soil quality, and potential geological hazards. One of the notable geological features on the site is an active fault. The presence of this fault is of significant concern due to its potential to generate earthquakes. Geologists have classified this fault as "active" based on evidence of recent fault displacement. This means that the fault has experienced movement in the relatively recent past and is considered capable of generating seismic activity in the future. Earthquakes have been instrumentally located along the fault, with the two most recent recorded events occurring on September 3, 2002, measuring ML=2.4 and 4.6. The Magnitude (ML) scale quantifies the energy released during an earthquake, and a 4.6 magnitude quake can produce noticeable ground shaking. The occurrence of earthquakes in the vicinity of the site is a critical factor for site-specific investigations and engineering considerations. Understanding the seismic hazard is vital for designing infrastructure and buildings that can withstand potential ground shaking and ensuring the safety of occupants. It's worth noting that the fault on the site was designated by the State to be in the Alquist-Priolo Special Studies Zone Act before initial site-specific investigations were conducted. This designation is a recognition of the fault's significance and potential risk in terms of seismic activity. In conclusion, the 3,300-acre site in Southern California presents a complex and challenging geological and topographic environment. The presence of an active fault and the history of seismic activity in the area make it imperative to conduct thorough geological and seismic assessments when planning any development or construction on the site. Proper engineering and safety measures will be essential to mitigate the risks associated with the geological and seismic characteristics of the site. Lessons Learned from this failures: ● This case exists because subsequent developers and their consultants attempted to circumvent the law. Understanding the geological composition and history of a site is essential for any development or construction project. The presence of folded and faulted sedimentary rocks and an active fault on the site necessitates a thorough geological assessment to ensure safety and stability. ● The fact that the fault was designated under the Alquist-Priolo Special Studies Zone Act before sitespecific investigations were conducted underscores the importance of understanding and complying with environmental and regulatory requirements. Ignoring such designations can lead to legal and safety issues. ● Overall, the lessons learned from this specific site underscore the importance of comprehensive geological and seismic assessments, environmental compliance, and responsible development practices in regions with complex geological and topographic features. These lessons are valuable not only for this site but for similar locations worldwide that face geological and seismic challenges. ACADEMIC INTEGRITY PLEDGE I swear on my honor that I did not use any appropriate aid, nor give such to others, in getting my assigned questionnaire for this course activity. I fully understand that cheating and/or plagiarism is a major offense, as stated in Section 15 of the TIP Student Manual and TIP Memorandum No. P-04, s. 2017-2018. I will wholeheartedly accept the consequences and sanctions that will be imposed on me appropriately once I have committed such acts. ____________ADARNE, JAYMEE LOU E.____________ SIGNATURE OVER PRINTED NAME
