Scour Remediation
Beach & Shoreline Erosion Prevention

Scour is the destructive effect that flowing water has on a submerged object.  When a man made object such as a bridge pier, pipeline, cable, etc. is submerged in flowing water the local effect is to increase the current velocity around the object.  This increased velocity has the tendency to remove or scour away the bottom material that supports the structure.  In the case of bridges, this has caused catastrophic failures of the structure with resultant loss of both property and life.  Scour has caused the failure of pipelines by first removing  pipeline cover and then the supporting material beneath the pipe which results in undermining.  Any structure that is submerged in flowing water is exposed to the potential effects of scour.  While engineers take scour into consideration when designing a project, changes in stream profiles can occur due to events such as flooding and the placement of other objects into the water upstream.

UCI performs scour remediation by two completely independent but equally effective methods.  Our primary repair is performed by using high strength cement grout that we pump into nylon fabric forms, also known as intrusion grouting.  This method uses specially fabricated nylon forms (commonly called bags) into which cement grout is injected by using pipes and hoses connected to a concrete pump.  Various height and width bags are available to suit the needs of each individual project.  Once the forms are pumped, grout is injected into the void behind the forms to underpin the structure.  Additionally, we can place and pump various styles of grout mats or articulating block mats to form a revetment which prevents future scour or erosion from occuring around structures.  Typical uses for mats are around bridge piers, abutments, wing walls, and over pipelines, cables, river banks, ditches, canals, and in settling ponds.  Grout revetments in fabric forms work equally well above or below water, and compressive strengths achieved are typically 10% higher than non-fabric revetments due to the fabrics ability to allow excess water to be forced out of the cementious mix.

Due to the nature of scour each project is designed on an individual basis.  We use a variety of mix designs to achieve the required 7 & 28 day compressive strengths and we have a fleet of well maintained pumps, hose and equipment ready to service your needs.  UCI has performed these services for PENNDOT, PA Dept. of General Services, Transcontinental Gas Pipeline, National Fuel Gas and others.

Our secondary method of scour remediation is a technology based product known as a fronded mat.  UCI is an authorized sales agent and installation contractor for a fronded anti-scour mat.  Each of these 4m x 5m mats consists of nearly 22,000 individual fronds of specially formulated polypropylene film.  As the mat is deployed, these fronds assume a "floating" position that because of the secure anchoring system establishes a structure analogous to natural seagrass.  As local currents transport sediment through the fronds, velocities decrease, and the sand/soil sediments are deposited and then compacted by the motion of the fronds.

When the mats are filled they become invisible.  The base and fronds are completely covered with deposited sand/soil; thus, the ocean floor or riverbed is rebuilt.  The mats simulate a fiber-reinforced berm to protect the structure or beach with approximately 100,000 pounds of hold-down per filled mat.

The anchoring system consists of high-strength, aluminum alloy or forged steel anchors that are hydraulically driven in the bottom.  The standard 4m x 5m mat is fitted with 16 aluminum anchors that provide 64,000 lbs. of non-gravitational hold-down per mat.

The mats are manufactured from chemically inert materials that will not break down in seawater, and the fronds have an immersed half-life of approximately 500 years.  Once the mats are installed, fish and other sea life have been observed swimming among the fronds, but there is no danger of the fronds harming any form of marine life.

In fact, these erosion control mats have environmental applications in the newly developing field of aquaculture.  Fish hatcheries can have the mats installed as an addition to fish habitats, and in this controlled environment, the current velocities are not sufficient to cause the mats to fill.  The fronds of the mats give young fish, or fingerlings, a place to hide from mature fish, thereby causing the mature fish to eat the pellet food supplied by the fish farmer.  This results in a higher yield for the hatcheries.

Erosion control mats are used to reverse scour and provide protection on  a variety of structures including bridges, intake and outfall pipelines, offshore oil structures, and telecommunication cables (a special 2.5m x 5m mat is available for cables).  Additionally, they may provide for more efficient operation in certain types of settling ponds, such as used in paper mills and the like.

One of the most exciting uses of erosion control mats are for coastal protection.  Each year, around the world, thousands of acres of beachfront property are lost due to the destructive effects of waves from storms, hurricanes, and typhoons.

Erosion control mats are designed to work with nature in the building of fiber-reinforced underwater berms.  Such berms reduce the impact of wave energy, thereby allowing a natural renourishment of beach sand from transported material.  In coastal applications, the mats provide two actions:

1. The berm builds up and slows down wave action, diminishing erosion.
2. The slower wave action slows the sand in the waves and causes it to be deposited on the beach side of the berm - eventually rebuilding the beach.

The mats provide unintrusive, environmentally friendly erosion control while contributing to natural beach renourishment.

Erosion control mats have been installed around the world for offshore oil exploration companies, pipeline owners, governmental agencies, beachfront property owners, and others.  Don't let the sea reclaim your land; let us show you how this product can provide permanent benefits for you.

This gas pipeline owner placed an earthen dike across the stream so that they could perform maintenance on their pipe. Once the pipe was repaired and fully bedded, UCI placed and pumped a grout mat over the pipe for protection and future scour prevention.	UCI has placed and pumped a 4" thick grout mat over the pipeline shown in the previous picture.	One of UCI's well maintained concrete pumps. We stock 4" and 3" concrete delivery pipe and hose to fully service our clients' needs.	This streambank has been protected against future scour and erosion by placing and pumping a grout mat. The mat extends below water to the bottom of the stream. Note that the mat has been toed into the bank at the top. If desired, the mat can be covered with soil, it can be left exposed and then be painted to match the surroundings, or it can be left as is.	Another grout mat designed to provide erosion and scour protection for this streambank. Note that the bank is critical for the support of the concrete foundation of the structure in the background.

A fronded mat is being readied for installation.  Note one of the 16 hold hold down anchors in the foreground and the protective netting over the mat. The netting is removed after anchoring the mat to the bottom which allows the fronds to float free.	The netting has been removed from this mat to show the fronds. Each 4X5 meter mat has approximately 22,000 fronds, each 5' high.	An artistic rendering of an installed mat with the fronds in the floating position. The insert shows how the hold down anchors deploy after being driven into the bottom.	This picture shows severe scour and undermining of a retaining wall. This beach front property is a 5 star resort in the Caribbean. The destructive force of storm driven waves has literally washed away the beach.

Another photo of the undermined retaining wall at this 5 star Caribbean resort. Again, note that there is no usable beach available to guests.	This is a photo of the same area as in the previous 2 pictures after installing fronded mats offshore. There is now a usable beach and the seawall has been protected against collapse.	This photo shows the same set of stairs as shown previously. Before installing fronded mats offshore, this set of stairs has been undermined by almost 24". After installing the mats, the undermining is gone and a new beach has been built where one did not exist before.	This is a frontal view of the same 5 star Caribbean resort after installing fronded mats. The resort now has a usable beach for their guests, and their property is protected.