Using Ground Improvements to Engineer Safer Solutions for Urban Development
Author: Sarah Kurtzer, EIT – Project Engineer
With the rise in construction activity and demand for additional and improved transportation services, the need to utilize sites with unsuitable soil conditions for new construction has increased substantially in the past few decades. Building on these unsuitable soils can result in bearing capacity failures, excessive settlement, liquefaction of soils, sinkholes in roadways, and landslides, to name a few. Previously, very few (and usually costly) methods were available to solve the issues associated with unsuitable soil conditions like uncontrolled fill, soft clays, loose coarse-grained soils, and collapsible soils.
Ground improvement, or ground modification, is the process of using mechanical means to improve the engineering properties of on-site soils. Ground improvement comes in many forms including densification of existing on-site soils, drainage and dewatering, preloading, reinforcement, chemical stabilization, and thermal and biological treatment. Selection of a ground improvement method should consider structural, geotechnical, environmental, and construction conditions, as well as reliability and durability. Some of the more common types of ground improvements are traditional compacting, deep dynamic compaction, rapid impact compaction, aggregate piers, and rigid inclusions.
Ground improvements have become a favorable option as technology has advanced. In many situations, improving the ground is a more economic and more efficient means of making a site suitable for construction. Ground improvements may eliminate the need for costly deep foundation systems such as driven piles, drilled shafts, and micropiles. Disposal costs may also be reduced as most ground improvement methods produce little to no waste, which is extremely advantageous on environmentally impacted sites.
The geotechnical industry is always developing and implementing new ways to work with difficult geotechnical conditions. Ground improvements provide alternative solutions to urban development that can be tailored to each specific site and project.