Geotechnical Design

Davies Geotechnical Inc. provides specialist design services to address the full range of geotechnical issues faced by property developers, owners, architects, structural engineers and other consultants.

We pride ourselves in continued education and technical excellence as well as familiarization of the state of the art in design and construction processes. Davies Geotechnical Inc. employ state of the art site investigation and analytical techniques in order to provide our clients with the best design solutions available.  We have recently adopted the use of strain dependant design techniques for the design of building foundations. Utilizing this procedure we are able to utilize soil stiffness value which are approximately 4 to 5 times higher than other design approaches. This has resulted in the ability to use much higher bearing capacities for foundation design, and therefore result in substantial cost savings to our clients.

Our expertise includes the following:

Foundation Design

  • Shallow foundations – bearing capacity analysis, footing settlement, subgrade modulus, seismic capacity.
  • Underpinning and foundation remediation for structures damaged by movement and/or settlement.
  • Deep foundations are commonly used on sites where the soils are either too weak or compressible to support the building loads. Davies Geotechnical Inc. has completed numerous projects involving the design of friction and end bearing piles including: timber, concrete, expanded base, steel H and pipe piles. Evaluation of lateral pile capacity and lateral pile stability during a seismic event is required on sites subject to liquefaction or loss of soil strength due to cyclic loading. Piling is typically a costly component of a foundation system and therefore understanding of pile capacity is important to providing a cost effective design. Davies Geotechnical Inc. has used PDA testing and pile load testing to maximize the efficiency of pile design.
  • Specialized foundations including: micro and macro piles designed for static and cyclic load conditions.
  • Seismic anchors and micro-piles.

Ground Improvement

A variety of techniques are used to improve the soils to support structures in soft ground conditions or conditions where soils are expected to undergo strength loss during an earthquake. These techniques include the following:

  • Vibro-replacement with stone columns.
  • Deep dynamic compaction.
  • Compaction grouting.
  • Soil mixing.
  • Jet grouting.
  • Compacted gravel columns.
  • Preloading.
  • Use of wick drains.
  • Seismic drains.

Pictures of Vibro-Replacement Stone Column Densification for Tower Development in Richmond, B.C.

                                                                                     

Preloading

Preloading is a technique used on soft soil site to reduce post construction building settlements to acceptable levels. This technique involves the placement of sand fill over a site is frequently used in soft soil sites in order to prepare the site for building construction and ultimately improve the performance of the building over its lifetime.

Slope Stability and Seismic Risk Assessment

Evaluation and understanding of slope stability is critical in sloping terrain areas where the effects of a slope movement or collapse can have catastrophic consequences. Understanding of the forces acting within a slope (both static and seismic) and understanding of the soil strengths and pore pressures is crucial to evaluation of the stability of a slope and to assess the potential for future slope movement.

Davies Geotechnical Inc. has completed numerous studies to evaluate the effects of cyclic loading on soil shear strength and specifically the potential for soil liquefaction.

Excavation Stability / Design of Temporary and Permanent Shoring Systems

In our rapidly expanding city, land value is at a premium and consequently many projects involve the construction of buildings that include the need for underground parking. This requirement for underground parking often results in the need to the design of a temporary support system to retain the soils and structures on adjacent properties.

Davies Geotechnical Inc. is specialized in the design of both temporary and permanent earth support systems and has completed numerous such projects in the Lower Mainland. The design of these support systems requires experience in the evaluation of soil and surcharge loads and the evaluation of soil strengths, particularly on sites where the soils are soft and weak and may be susceptible to strength loss.

Temporary support systems routinely designed by Davies Geotechnical Inc. include:

  • Shotcrete tied back with soil or rock anchors.
  • Soldier pile walls tied back with soil or rock anchors.
  • Sheetpile walls, cantilever, internally braced, and tied back with soil anchors.
  • Micro-pile walls.

Retaining Wall Design

Many large and small scale projects have the need for the design of retaining walls. These walls include: reinforced concrete retaining walls, gravity walls, reinforced soil slopes (mechanically stabilized earth, segmental retaining walls (SRW), and permanent tie-back walls (anchored shotcrete walls).

The use of segmental retaining walls has been more popular given the cost advantages and ease of construction of these wall systems in comparison with other wall systems. Davies Geotechnical Inc., through access to a number of universities maintains, an understanding of the cutting edge testing and design procedures of these wall systems in order to provide our clients with safe and cost effective solutions.

Davies Geotechnical Inc. teamed with Nilex and Tensarcorp in 2006 and 2007 to design a number or large MSE structures at the site of the 2010 Olympics in Whistler. The tallest of these structures was 15m in height, constructed at a 10 vertical to 1 horizontal slope using the Sierra Scape system.