Sub Sections:
1
2
3
4
5
6
7
8
9
10
11
12
Pages:
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
Micro Piles |
Pressure Grouting |
Rock Anchors |
Permeation Grouting
Soil Nailing |
Compaction Grouting |
Micropiles |
Injection Grouting |
Chemical Grouting
Our
techniques apply when adding new structures:
especially
rock anchor,
microfine cement,
soil nailing,
micropile
installations for
foundation support.
We
specialize in
slope stabilization,
anchors,
permeation grouting,
foundation repair
and support,
grouting,
soil nails,
rock drilling,
micropile installations, and
sinkholes. We
use a
problem-solving approach geotechnical
architecture of buildings, bridges,
water plants, sewage plants, tunnels,
sinkholes,
caisson,
shoring,
underpinning,
agriculture, and
roads
construction. We
are experienced in these applications:
micro piles,
sinkhole repair,
permeation grouting, pressure
grout,
soil nails,
chemical grouting,
micropiles,
compaction grout, and
rock anchors.
Our specialties are
rock anchor,
acrylamide and
compaction grouting,
mini piles,
sinkhole repair,
micropiles,
acrylamide grouting, and
soil nailing.
We will continue to dedicate ourselves to
excellence,
including
insurance mortgage, in our performance, in our
integrity, and in our relationships with our
customers. We will carefully weigh our
decisions, actions, and results to make sure
that we remain the most trusted name in the
geotechnical contracting industry. Please
visit our website
http://www.rembco.com/.
Add Concrete Construction URL
Artistic Business Community Related Construction Industry Computers Education Relevant Entertainment Health Internet Family Recreation Science Shopping Society
|
JULY
1997
Slurry Displacement Piles
9-8
The amount of time that the drilling slurry is in the drilled hole has a direct effect on the
thickness of the filter cake that develops on the sides of the drilled hole. Since positive
effective stress is a continuous phenomenon, the build-up of filter cake will continue so
long as the pore spaces between the soil grains have not filled in. In general, the longer the
drilling slurry is present in the drilled hole, the more filter cake will accumulate on the
sides of the drilled hole. Sometimes this results in the presence of excess filter cake build-
up, which must be removed before concrete can be placed in the drilled hole.
The important thing to remember about filtration is that the filter cake helps to temporarily
stabilize the sides of the drilled hole before concrete is placed. Filter cake is not meant to be
left in place during concrete placement operations. If the filter cake is thin enough, the
rising column of concrete will scrape it off the sides of the drilled hole. However, if the filter
cake has excessive thickness, the rising column of concrete may not scrape all of it off the
sides of the drilled hole. The remaining filter cake may act as a slip plane between the pile
concrete and the sides of the drilled hole, resulting in the reduced skin friction capability of
the pile.
Sampling and Testing Drilling Slurry
Sampling and testing of drilling slurry is an important quality control requirement.
Responsibility for testing and maintaining a drilling slurry of high quality is placed on the
Contractor by the contract specifications.
The apparatus used to sample drilling slurry must be capable of sampling the drilling
slurry at a given elevation in the drilled hole without being contaminated by drilling slurry
at a different location as the sampler is removed from the drilled hole. This is necessary
because the contract specifications require the drilling slurry to be sampled at different
levels in the drilled hole. The sampler must also be large enough to contain enough
drilling slurry to perform all the required tests. The apparatus generally consists of a hollow
tube with caps positioned above and below the tube on a cable that is used to lower the
sampler into the drilled hole (Figure 9-4). Once the sampler has been lowered to the desired
level, the drilling slurry contained in the hollow tube at that level is contained by activating
the caps so that the ends of the tube are sealed. The sampler is then removed from the
drilled hole and the drilling slurry contained is tested.