|
|
COMPOSITION AND MATERIALS
Stingray anchors are made of hot dip galvanized ductile iron. Structurally compatible anchor rods and end terminations
for guy line or retaining structures are available for all anchor models. Stingray anchors use Solid Core Rod (SCR).
TECHNICAL PERFORMANCE ISSUES
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 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.
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 dependent upon the grout length and soil type. Both the CTB and SCR exceed the deformation characteristics
of ASTM 615 rebar.
For retaining structures, Stingray anchors should be installed a minimum of 10 feet behind the failure plane after
proof testing. A minimum overburden of 7 feet must be maintained for Stingray anchors.
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. |
