Geo-Institute and AEG Arizona Chapter Event 

Register Now! 

Please join us for a joint meeting hosted by ASCE Geo-Institute and Association of Environmental and Engineering Geologists (GI and AEG) chapter monthly get-together and technical seminar at McFate Brewing Company on Wednesday, June 21, 2017 at 5:30 pm. We will have a presentation by Enamul Hoque, P.E. on "Building Structures on Landfill".

We encourage members to register and pay online prior to the event, so we can have accurate headcount. Thank you for your consideration!

 

‘Building Structures on Landfills’ by Enamul Hoque

 During last 12 to 15 years, Hoque and Associates, Inc. (HA) has been involved in geotechnical work for developing structures on old closed to operation landfills. Development on closed landfill is subject to some risks and some regulatory compliances. However, once these two hurdles are overcome or mitigated to a reasonable level for development to function with safety and performance as desired. The regulatory requirements prohibit increased infiltration of water into the waste prism so that leachates or landfill gas productions are not increased. In addition, regulations also prohibit not to cause any exposure of the waste to the environment to increase safety hazard for health and the environment. The geotechnical risks involve settlement and related movement of structures. Settlement in a landfill environment constitute four components: Settlement due to mechanical compaction of loosely placed waste and debris materials; Settlement due to consolidation; Settlement due to raveling and particle migrations and secondary compressions; and Settlement due to decomposition of organic materials present within the waste prism.

 While the settlements related to these components can be minimized greatly to an acceptable level for a structure, the process of chemical and bio-chemical decomposition could not be stopped with the presently available technology. As such, while diminished greatly, settlement due to decomposition of organics will continue to some extent depending on the lignin content of the organics.

 The process that HA had utilized to minimize settlements of structures on landfill involves deep dynamic compaction. In this method, a tamper of 16 to 30 ton is freely dropped from a height of 45 to 85 feet repeatedly on the ground that will receive the compaction. The location of the drops are selected on a grid pattern at approximately 12 top 15 feet spacing. The number of drop, drop height and tamper weight chosen is dependent on the type of waste materials and structures that would be built. Generally, construction and demolition debris landfill are best suited for this method and HA has successfully completed the project at Tempe Marketplace. This project is being in service for almost 10 years without any issue. Few other projects that contained some organic materials, HA had modified the method a little by adding dynamically injected stone column. However, organic content was limited to less than 10 percent. Currently, HA is also implementing an additional methodology of using earth reinforcement with geogrid materials in combination with deep dynamic compaction and dynamically placed stone column at areas where organic content exceeded 20 percent of the total weight of the waste materials. The minimum fill height above the landfill was determined using Westergaard stress distribution.   

 

BIOGRAPHY

 Enamul Hoque, P.E., D.GE, F.ASCE

Hoque & Associates

 Enamul Hoque, P.E., D.GE, F.ASCE graduated with a B.S. Eng degree from Bangladesh University of Engineering and Technology in 1973 and inn 1985, he completed his Master’s degree in civil engineering from Arizona State University and started working in the southwestern United States in 1986. In 1997, he started Hoque & Associates, Inc., with two engineers and built the company to its current 15-person size. Hoque & Associates, Inc. provides innovative and cost-effective engineering and sustainable solutions to Arizona’s projects including work on old landfill reclamation, new landfill design, and value engineering. He has been awarded numerous social and professional achievement awards including Arizona State University’s School of Sustainable Engineering and the Built Environment “Outstanding Alumni” in 2017 and prestigious ASCE’s John C. Park Award for his outstanding contribution to advance the profession of civil engineering in 2011. His notable work includes restoration of the Salt River, Construction of Deep Water Port for US Navy at Umm Qasr, Iraq, and development of regional marketplace on landfill in Tempe, Arizona. He also established a Girls College near his village in Raipura Upzilla which houses 350 students with astounding performances. He has won numerous awards from the state of Arizona and US Department of Housing some of which was broadcasted in Public Broadcasting System Television especially his technical innovation and philanthropic work. Public Broadcasting Services broadcasted his life story as part of his award Spirit of Enterprise in 2007 awarded by the Arizona State University. Arizona State University named geotechnical laboratory “EM Hoque Geotechnical Laboratory.” Mr. Hoque received Distinguished Achievement Awards from Arizona State University's Ira Fulton College of Engineering. His work on river restoration and utilization of appropriate technology to solve complex engineering problem earned him excellent reputation in his field.