Applied Research Projects
   

FLUORESCENT SAND TRACING IN COASTAL ENVIRONMENTS
 

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Clients:  U.S. Army Corps of Engineers, U.S. Coast Guard
 
The study of coastal sediment transport is complex.  Attempts to quantify sand movement through traditional means such as direct observation, coastal surveying and area photo analysis are not always sufficient.  An alternative method that we have successfully applied involves the use of beach sand that has been coated with fluorescent dye.  Following release, sand samples can be collected over time and viewed under a "black" light to determine the extent of fluorescent sand content.  Subsequent mapping of the dyed sand allows an interpretation of sand movement direction and transport rate.
 
Areas of Application

Study of Shoaling - San Diego Harbor
 
Release of two dyed sands (red and green) at two possible source locations to determine shoaling mechanism
 
Sediment collection (both above- and below-water) over a two month period indicated the presence of only one dyed sand color in the shoal, thereby definitively establishing the source
 
Coastal Processes in a Pocket Beach - Crescent Bay, Laguna Beach, CA
 
Allowed a determination of sand movement within this confined cove over a period of one year
 
Following release of the tracer sand, winter storm erosion transported the beach sand offshore
 
Once the sand returned to the beach in the spring, dyed sand was found on the beach, rather than up- or down-coast
 
The study provided evidence that the sand within Crescent Bay remained within the cove and was not lost or replenished by sand moving alongshore seaward of the rock headlands that bound the bay
 
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GEOTEXTILE ARMOR SYSTEMS
 

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Clients:  County of Los Angeles Department of Beaches and Harbors, Various Members of the Petroleum Industry
 
Geotextile armor has proven to be appropriate for projects in remote areas that lack economical sources of quarrystone, and for projects with limited design lives.  Since 1980, Coastal Frontiers personnel have undertaken concept development, hydraulic model investigations, prototype testing, and end-of life removal for a wide variety of geotextile armor systems ranging from small sand bags to large sand- and grout-filled mattresses.  Applications have included emergency protection for structures on Southern California beaches and man-made islands in Alaska with service lives as long as 20 years.
 
Innovations of Note
 
Quantification of sand bag stability and runup characteristics through large-scale hydraulic model testing
 
Design of underlying geotextile filtration panels to speed installation, enhance stability, and reduce risk of fill loss for geotextile armor
 
Development of filling methods, lifting mechanisms and placement methods for sand bags as large as 6.5 tons
 
Design of secure closures for sand bags
 
Development of long-life fabrics with an intended Arctic service life of 40 years
 
Design of bag retention systems to prevent the loss of damaged units into the water column
 
Development of removal techniques suitable for use at the end of the geotextile armor service life
 
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MULTI-YEAR ICE FLOE CHARACTERISTICS AND DYNAMICS
 

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Clients:  Joint Industry Study (AOGA Project No. 280)
 
Multi-year ice floe impacts constitute a major design consideration for fixed offshore structures in cold regions.  To gain an understanding of the characteristics and dynamics of multi-year ice during the open-water season, field studies were conducted in two successive years.  The parameters investigated included winds, ocean currents, water mass properties, ice floe morphology and salinity, and ice floe translation and rotation.
 
Study Objectives
 
Measure the motions and physical characteristics of large-diameter multiyear ice floes, while simultaneously measuring the oceanographic and meteorologic driving forces
 
Relate ice floe motion to the measured environmental parameters
 
Evaluate field measurement techniques applicable to future research and operational ice monitoring
 
Key Aspects of the Field Program
 
Acquisition of high-resolution ice floe motion data using satellite positioning systems
 
Measurement of frontal and mesoscale circulation using Lagrangian drift buoys
 
Detailed delineation of thick floe morphology using a high-speed thermal drill
 
Analysis and interpretation of the relationship between ice floe motion and the environmental driving forces, including a numerical simulation of the measured ice floe trajectories
 
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RIVER OVERFLOOD, STRUDEL SCOURS AND ICE GOUGES
 

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Clients: U.S. Department of the Interior, Bureau of Ocean Energy Management, Regulation, and Enforcement (BOEMRE)
 
Offshore hazards to the safe development of oil and gas resources in cold regions include the unique processes of strudel scouring and ice gouging.  Since 1995, Coastal Frontiers personnel have conducted annual offshore surveys to document the frequency and severity of these phenomena off the coast of Alaska.  A multi-year investigation for the Minerals Management Service (now BOEMRE) sought to define the character and variability of river overflood onto the sea ice, while an analysis of measured strudel scour characteristics led to the first-ever characterization of scour zonality and the associated risks to subsea pipelines.  The findings these and similar research efforts have guided the design of all three subsea oil and gas pipelines that have been installed in the Alaskan Beaufort Sea.
 
Methods
 
Helicopter overflights during on-ice river overflood in the spring to map flood limits and individual strudel drains
 
Multi-beam and side scan sonar surveys to locate and quantify strudel scours and ice gouges
 
Integration of recent findings with gouge and scour data dating back to the 1970s
 
SCUBA diving and remotely-operated vehicle (ROV) operations to acquire “ground truth” information for the calibration and verification of sonar data
 


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FREEZE-UP PROCESSES
 

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Clients:  Joint Industry Study
 
Ice-infested waters and heavily travelled maritime routes present unique challenges to oceanographic data collection.  Coastal Frontiers has obtained oceanographic data in the Beaufort Sea to support the design, construction, and maintenance of various projects.  The parameters studied include the following:

  Wave height, period
  Curren speed and direction
  Water level
  Storm and ice movement conditions
  Time lapse photos of storms and ice events
  Data analysis correlates the wind, wave, storm surge, and current data to better predict extreme ocean events.

Specific deployment and recovery techniques developed to ensure the
long-term safety of data collection systems include:

  Ocean instrument deployments using both boats and helicopters
  Bottom-founded tripods to minimize the potential for damage
  or loss from deep-keeled ice floe or ship impacts
  Instrument recovery through the Arctic ice cover in November- December following stabilization of the winter ice sheet
  Recovery after freeze-up ensures complete data collection during severe storms of September-October.
 
Key Aspects
 
Acquisition and analysis of publicly-available meteorological data, ice charts and satellite imagery
 
Acquisition and analysis of proprietary RADARSAT II images
 
Fixed-wing and helicopter-based reconnaissance missions to investigate large-scale features noted on satellite imagery and small-scale features beneath the resolution of the satellite imagery
 
Analysis of the nature and timing of freeze-up processes, including an assessment of inter-annual variations as well as long-term trends indicative of a changing Arctic climate
 
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ON-ICE INCIDENT RESPONSE
 

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Clients:  Member of the Petroleum Industry
 
As break-up approaches in the Arctic Ocean, the ability to respond to incidents such as oil spills is impacted by the deteriorating condition of the winter ice sheet.  Particular concerns include the transport of work crews and equipment to the incident site and the recovery of spilled fluids, both of which require specialized vehicles that exert low ground pressures.

During a one month period immediately prior to break-up of the sea ice, Coastal Frontiers personnel conducted on-ice tests to quantify the capabilities of various types of response equipment.  The findings were used to identify an equipment spread suitable to conduct late-winter incident response efforts.  
 
Study Tasks
 
Devise a test plan to evaluate the performance of candidate incident response equipment, including:
- Amphibious ditchwitch trencher
- Amphibious backhoe
- Tucker Sno-Cat
- Light-weight tractor equipped with snow blower
- Cat 966D loader equipped with ice trimmer
- Amphibious Haagland personnel/small equipment carrier
 
Measure equipment speed, rate of production (ice cutting, snow collection, ice trimming), and evaluate operational safety

 
Conduct three field studies during early, mid-, and late June to observe the limitations imposed by the degrading ice sheet
 
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INNOVATIVE BEACH SEDIMENT RETENTION CONCEPTS
 

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Clients:  City of Long Beach, CA; U.S. Army Corps of Engineers
 
Sediment retention structures provide a means to decrease the cost and frequency of beach nourishment and to increase the level of storm protection for coastal development.  While the function of traditional rock groins is fairly well understood, these structures have fallen out of favor with the resource agencies or the general public in many locales.  Coastal Frontiers has actively investigated innovative sediment retention concepts, including nearshore submerged reefs, a perched beach, and low-profile goetextile groins.  The feasibility and effectiveness of these sediment retention concepts has included numerical simulations, physical model studies, and prototype installations. 
 
Numerical Studies:  Artificial Reefs and Groins - Oceanside, CA
 
Conduct Monte Carlo simulation of wave and water level conditions to forecast shoreline evolution over a 50-yr period
 
Assess shore protection alternatives including beach nourishment, traditional groins, nearshore submerged reefs, and combinations of nourishment and sediment retention
 
Salient Findings: structural alternatives reduced shoreline erosion, but capital cost was high
 
Physical Modeling:  Perched Beach - Long Beach, CA
 
Perform 3-D moveable bed hydraulic model study to evaluate the effectiveness of perched beach alternatives to mitigate erosion
 
Replicate natural patterns of erosion in the wave basin
 
Test two perched beach configurations using the same wave conditions used to reproduce the natural beach behavior
 
Salient Findings: erosion was reduced but alongshore currents accelerated due to water level set-up in the nearshore region
 
Prototype Testing:  Low-Profile Geotextile Groins - Long Beach, CA
 
Install three temporary low-profile geotextile groins to assess changes in shore erosion rate
 
Document performance through periodic surveys
 
Salient Findings: low profile groins reduced shoreline erosion with minimal adverse impacts
 
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