Earth dams and levees, Transport corridors, Geotechnical Engineering Design
Earth Dams & Levees
The problem
Tens of thousands of earth dams and levees around the world are aging increasing risk of seepage and failure.
Current methods of investigation include (Cone Penetration Test (CPT), Becker Penetration Test (BPT), standard Penetration Test (SPT) or Shear Wave Velocity test (SWVT or MASW)). Interpolation between the discrete sample points obtained from these methods can miss critical areas of concern
Echo Geotech’s Solution
Echo Geotechnical’s Landstreamer technology provides continuous shear moduli and sub-dam seismic profiling to image information between discrete point tests with a non-destructive profile along the top, toe or sublevels of these dams
Echo Geotech Advantage
Establish weak portions of the dam requiring mitigative engineering
Investigate soils structure underneath the dam structures that may have been eroded over time or have high potential of giving way due to low shear strength.
Jointly conduct SWVT testing and investigate 10-50m below the existing ground surface in a single pass.
Deliver geologic data, deeper data, high resolution continuous profiles with no surface disturbance or intrusive drilling along the earth dams
Lower cost with the added benefit of optimizing the placement of the more expensive CPT and drill tests if required.
The problem
A key characteristic of soils required by geotechnical engineering investigations is the shear moduli or strength of the top 30 meters of soil to ensure overlying buildings/structures are not at risk of collapse due to soil structure.
Currently drilling and/or CPT's are conducted at discrete points within a construction site. Low shear strength areas between or below these discrete points are often missed increasing the risk of catastrophic hazards in the future or additional unplanned construction costs.
Echo Geotech’s Solution
Echo Geotechnical’s non-intrusive Land-streamer is ideally suited to urban environments and provides continuous profiles of the subsurface up to 200 metres in depth reducing the risk of undetected potential hazards
Echo Geotech Advantage
High resolution Land streamer profiles cost less than penetration tests and may reduce the number of penetration tests required and optimize their placement.
Identifying areas of weak soil strength along continuous profiles prior to construction should mitigate the risk of significant disastrous consequences during and after construction.
Geotechnical Engineering
Transportation Infrastructure
The problem
Subsurface characterization in transportation corridors is key to initial construction design and long term maintenance including investigations of roadway subsidence and sinkholes for example.
Key geotechnical parameters may include bedrock depth, rock type, layer boundaries, water table, weak zones, expansive clays, natural cavities and/or abandoned mines etc..
"Geophysical" techniques routinely used for geotechnical highway and railway engineering investigations are often limited either in depth of penetration and/or to simple stratigraphy:
GPR methods for example are limited to a few meters in clays and tills
Refractions methods are limited to 2 or 3 layers with increasing velocity
MASW techniques can provide shear velocity but only to limited depths and only in simple stratigraphy
Echo Geotech’s Solution
Continuous profiles of the subsurface using Echo Geotechnical’s non-intrusive Land-streamer ideally suited to data collection in transportation corridors.
MASW, SH AND P-wave data collection in a single pass
The vertical resolution of shear waves acquired using the Landstreamer is 5 times that of conventional p-wave seismic and can provide usable information as shallow as 6-8 meters depth and as deep as 200+ meters.
The design and data analysis of our system can efficiently cover 3-4 km/day with interpreted results provided in most case within 24-48 hrs
Echo Geotech Advantage
Continuous seismic profiles support deeper investigations for hazards such as abandoned mine workings, low shear strength alluvial clays, voids and complex lithologies such as buried channels.
Continuously samples the subsurface between known drill holes or other data points.
Ideally suited to work on paved or gravel roads as the 3 component geophones travel on 10" long sleds that drag behind the vibrator - no "planting" of geophones typical of most seismic surveys required.
Shear wave reflection technology is a "new" offering that characterizes the shear velocities of the underlying material, identifies voids and mine workings accurately to depths of 100+meters.