procedure should be left to the discretion of the
contractor to meet the performance criteria. When a
specific grouting procedure is required to develop
the design capacity, the procedure should be
included in this paragraph.
**************************************************************************
3.3.5.1
General
Within the bond length, grout placement shall proceed such that the hole is
filled in a manner to prevent air voids. The soil anchor hole shall be
progressively filled with grout and maintained completely full from bottom
to top of the zone until the grout has set. Grouting of a soil anchor hole
shall be performed within 48 hours of the time the hole is drilled.
Grouting may be accomplished through the casing pipe, grout tubes,
hollow-stem augers or hollow drill rods. The grouting procedure used shall
provide soil anchors which meet the specified design capacity.
Post-grouting will normally result in higher bond values.
3.3.5.2
Gravity Grouting
Gravity grouting shall proceed from the bottom of the hole to the top of
the [bond zone] [hole].
3.3.5.3
Pressure Grouting
The method of pressure grouting shall be determined by the Contractor and
proven in the demonstration anchor. Production anchors shall be grouted
using the methods and target pressures that were used on the acceptable
demonstration anchor. Grouting pressures and pumping rates shall be
controlled to prevent ground surface heave or fracturing. Grouting
pressures shall be incrementally increased until a refusal is reached or an
acceptable amount of grout is pumped.
3.3.5.4
Post-Grouting
**************************************************************************
NOTE: Post-grouting is performed using grout tubes
with special check valves in the grouting zone which
are installed with the tendon. Post-grouting may be
utilized as additional pressure grouting after
initial grout has set to increase the bond values
for anchors. It may also be used, when
post-grouting tubes have been installed, for
increasing the bond values of anchors which fail
load tests. The maximum grouting pressure is
determined by the pressure-volume characteristics of
the soil. Three phases of post-grouting is
considered to be the practical limit.
**************************************************************************
The number of phases of post-grouting shall be determined by the Contractor
and proven in the demonstration anchor. Production anchors shall be
grouted using the methods and target pressures that were used on the
acceptable demonstration anchor. Grouting pressures and pumping rates
shall be controlled to prevent ground surface heave or fracturing.
Grouting pressures shall be incrementally increased until a refusal is
reached or an acceptable amount of grout is pumped.
SECTION 02490
Page 36
Previous Page
