Geotechnical Engineering

Eon has extensive experience in international geotechnical projects, ranging from landfill development to dewatering for landslide stabilization. Our team members are experienced with the implementation of dewatering and pressure relief wells, drives, injection curtains, and monitoring and testing systems, as well as the preparation of documentation and presentations for local authorities, international panels of experts and symposia.

The importance of proper landfill site selection and development cannot be overstated in todayís environment. Hydrogeological mapping, the design of testing, monitoring and engineering measures, and all sets of permitting and compliance measures are inevitable requirements for this highly sensitive sub-specialty of geotechnical engineering. Our expertise was critical to the evaluation of the Manukau Sanitary Landfill, in Auckland, New Zealand. When proposed, the Manukau Landfill was the largest landfill project in New Zealand. The hydrogeologic report provided by our professionals enabled government officials to make informed decisions with respect to the risks versus the benefits of the proposed site.

Eon professionals selected locations and provided conceptual engineering designs for three emergency hazardous waste landfills in Europe. Avoiding incidental secondary pollution during emergency cleanup operations resulted in millions of dollars of cost savings.

Eonís experience with landslide stabilization and dewatering is evidenced by the work performed on the Clyde Power Project, in New Zealand. Valued at roughly three billion dollars, the project involved stabilization work on the surrounding mountains of the largest concrete gravity dam and lake in New Zealand. The work involved a geotechnical investigation and an assessment of the landslide characteristics. Eon engineers helped to stabilize the slides and prevent a catastrophic wave generation that would have toppled the dam and inundated the city of Alexandria, with over 30,000 inhabitants.


Typical Geotechnical Projects:

Name of Project: "Clyde Power Project"
Client: Electricity Corporation of New Zealand and Works Consultancy, New Zealand

Roughly a three billion dollar project that involved stabilization work on the surrounding mountains of the largest concrete gravity dam and lake in New Zealand. Work involved geotechnical investigation, assessment of the landslide characteristics and the effect of the toe inundation. Major landslides with toes at sea level and crests more than four thousand feet (4000 ft) above sea level were discovered along the dam site at river Clutha, upstream of Alexandra (over 30,000 inhabitants). If triggered, landslides would generate a wave topping the dam and inundating Alexandra. Highly complex groundwater conditions in Cromwell Gorge were shown to exert a major controlling effect on the landslides.

Development of geotechnical and hydrogeological conceptual and numerical models and the visualization of those models became one of the indispensable tools for predictive stability analyses. The models were based on a wide range of data collected from piezometers; drilling records; drainage response; geotechnical, permeability and hydraulic testing; seismic profiling; resistivity surveys; groundwater chemistry monitoring; and field measurements, as well as interactive numerical modeling. The remedial measures included extensive drainage via tunneling and inclined drilling, buttressing, and slope trimming. These were designed and implemented to offset the lake filling effect and to mitigate hazards such as reservoir blockage and wave generation.

Accomplishments:



Name of the Project: "Central Bohemia Region - Emergency Hazardous Material Landfills"
Client: Central Bohemia Region Government

Selection and design of emergency hazardous waste landfills in Central Bohemia involving desk study, sampling and field measurements and laboratory testing for water soil and bedrock quality, geotechnical parameters testing, geobotanical investigation, remote sensing, geophysical investigation, hydrogeological mapping, evaluation of climatic conditions and compilation of thematic maps. Detailed studies targeting selected areas included determination of urban, socioeconomic, geologic, geomorphologic, pedologic, geotechnical, hydrologic and hydrogeological impacts of the landfill development and engineering design of preventive and construction measures. The measures included retention and supporting dams, geotechnical work, collection drains, retention pits, liners, monitoring systems, liquidation of retained leachates, recultivation, future land use options, and detailed budgets for government approval.

Accomplishments: