How Stingray earth anchors works

Stingray earth anchors, a patented labor and time saving device, work like a toggle bolt in soil. The anchors are driven into the ground with conventional equipment (with no excavation and no grout), providing a safe and environmentally sensitive installation.

After driving the anchor to the required depth, the drive steel is removed and an upward pull on the anchor rod rotates the Stingray earth anchors into a perpendicular “anchor lock” position in undisturbed soil. After the anchor is tipped it can be simultaneously load tested. The result: superb holding capacities. Stingray earth anchors systems offer breakthrough earth anchoring technology for applications where heavy capacities are required.

Many of our customers utilize Stingray earth anchors for tie-backs and excavations shoring with superb economic advantages. The bottom line is Stingray earth anchors is the ideal solution for a wide range of soils and applications requiring superior holding capacities.

This article comes from earthanchor edit released

Manta Ray Installation

Installation Equipment

Drive Steel
Drive steel and accessories are available from Foresight Products for all Manta Ray and Stingray anchors in basic lengths of 3 feet, 6 feet, and 8 feet. Multiple sections are coupled together with specialized couplers to achieve the required depth of installation. Manta Ray and Stingray drive steel are not interchangeable.

Load Locking Kits
For Manta Ray, the LL-1 is a 10-ton fast acting jack with an 8-inch stroke. The direct reading gauge and rod gripping jaws make load locking easy and quick. For high capacity Stingrays, the LL-40 is a 20-ton jack with a 10-inch stroke. The base and jack are self-aligning to the actual installed angle of the anchor. Both kits require open center hydraulic flow of 2 to 8 gallons per minute and a maximum pressure of 2,000 psi. A power supply is not included with these load-locking kits, it must be provided separately. Foresight Products models GPU18- 8 or GPU-2 are suitable for the LL-1. GPU18-8 is required for the LL-40.

Installation Methods

Vehicle Mounted Breakers or Compactors :
Boom mounted demolitions or compactions are very effective for driving Manta Ray and Stingray anchors.
This method requires a special tool in the breaker or a socket welded to the bottom of the compactor to hold the drive steel.
Skid steer loaders, backhoes or excavators work well.

4,000 to 16,000 lb. vehicles with 250 to 500 foot-pound pavement breakers are best for Manta Rays, and 16,000 to 30,000 lb. vehicles with 500 to 1,000 foot-pound pavement breakers are best for Stingrays.

Breaker tools and vibro sockets are available upon request.

Rock Drills :
Top hammer or down-the-hole hammer rock drills are very effective for installation of Manta Ray and Stingray anchors.
For hard soil or weak rock installations, the drill can be used to drill a pilot hole. We can provide striker bar adapters for these types of drills.
Rock drilling steel can also be modified to drive Manta Rays and Stingrays.

Manual Installation :
In some applications, Manta Ray anchors are driven into the soil with a 90 lb. pavement breaker and coupled drive steel.
Pneumatic or hydraulic breakers are acceptable, but a 90 lb. weight class breaker is necessary.
Manual installation of Stingray anchors is not recommended.

(This article comes from ABC Diving editor released)

Some Technical Performance Issues to Manta Ray and Stingray Earth Anchors

Manta Ray and Stingray anchors are tensile anchors designed to work well in soils with SPT blow counts (N) from 7 to 50. The smaller anchor models are used in harder soils or where lowers loads are required. Larger anchors are used in softer soils. In harder soils, the installed capacity is limited by the ultimate strength of the anchor. In softer soils, it is limited by the soil strength. Soils with blow counts of 35 to 50 and higher, often require the installer to drill a 4-inch diameter pilot hole for Manta Ray or a 6-inch pilot hole for Stingray prior to installation in order to achieve an efficient installation time.

Although they are not intended for installation in rock, some models can be successfully installed into rock formations with low Rock Quality Designation (RQD). Typically, a pilot hole is required for these installations, but sometimes anchors can be simply driven into weathered, layered, decomposing rock.

Manta Ray and Stingray anchors are designed to react tensile loads along the axis of the anchor rod. They are not designed to react compressive, lateral, or shear loads, however, they can be made to do so by the addition of grout, which will increase the holding capacity,
sometimes very significantly.

The increase is dependant upon the grout length and soil type. Both the CTB and SCR exceed the deformation characteristics of ASTM 615 rebar.

For retaining structures, Manta Ray anchors should be installed a minimum of 6 feet behind the failure place after proof testing. Stingray anchors should be installed a minimum of 10 feet behind the failure plane after proof testing. A minimum overburden of 4 feet must be maintained for Manta Ray anchors and 7 feet for Stingray anchors.

Manta Ray and Stingray anchors can be proof tested up to 90% of yield strength. Working loads are typically between 50% and 90% of the proof test value.

(This article comes from GeoSolutions editor released)