1 scope
This technology is applicable to general
industrial and civil buildings and structures of the Foundation pit (Groove)
and trench manual excavation.
2 construction preparation
2.1 the main equipment: sharp, flat
crowbar, hammer, trolleys, ladders, iron pickaxes, crowbars, slope gauge, steel
wire, small or 20th, and so on.
2.2 operating conditions:
2.2.1 prior to excavation, underground
pipes and other obstacles should be found out, and according to the
construction plan requirements, construction of aboveground and underground
obstacle clearance in the region and dealt with.
2.2.2 location of the building or structure
or ground positioning control lines (piles), standard and size of gray line of
the trench shall be subject to inspection, and through pre-screening
procedures.
2.2.3 to clean the flat surface, slope
drainage in the construction area, dig into the temporary drains.
2.2.4 night-time construction, should be
reasonable arrangements for operation to prevent wrong to dig or over.
Construction site according to the lighting needs to be installed, in dangerous
places should be set clearly marked.
2.2.5 of Foundation pit excavation below
the groundwater level (trough), when the tunnel, according to the local
geological information takes measures to reduce groundwater levels generally
fall below 50cm the bottom of excavation and excavation.
2.2.6 familiar with the drawings, technical
clarification.
3 operational processes
3.1 process:
Determine the sequence and excavation
slopes along the grey line → cut out slot horizontal excavation contour → → → trim tank side end
of Qing dynasty
3.2 determination of slope:
3.2.1 in the natural humidity of the soil,
excavation (Groove) and when the trench, when provisions of the digging depth
does not exceed the following values, do not slope without support.
3.2.1.1 dense, medium dense sand and gravel
soil (filled with sand) 1.0M;
3.2.1.2 hard plastic, plastic, clayey silt
and silty clay 1.25m;
3.2.1.3 hard plastic, plastic clay and soil
detritus (filled with clay) 1.5M;
3.2.1.4 hard clay 2.0M.
3.2.2 above provides depth in 5M, when the
soil with natural moisture, construct a uniform hydrogeological conditions,
without water, without support of Foundation pit (Groove) and pipe must slope.
Provisions of the steepest gradient of the slope should be consistent with
table 1-1.
3.3 in accordance with base and unearthed
in the soil and site conditions, such as to determine reasonable excavation
sequence, then further split into hierarchical average excavation.
Table 1-1 of various types of soil slope
Slope (height: width)
Top load-free quality has static load top
load
1 medium dense sands 1:1 1:1.5
2 medium dense soil detritus (filled with
sand) 1:0.75 1:1 1:1.25
3 hard plastic light loam 1:0.67 1:1
4 medium dense soil detritus (filled with
clay) 1:0.50 1:0.67 1:0.75
5 hard plastic clay, clay 1:0.33 1:0.67
6 old loess 1:0.10 1:0.33
7 soft (after it has been well-point
dewatering) 1:1.00--
3.3.1 excavation of shallow foundations,
such as when the slope should be straight edge cut out grooves along the grey
line contours.
3.3.2 excavation Groove pit:
3.3.2.1 shallow Strip foundations.
Excavation of clay layer from top to bottom, each layer of depth to 60cm is
appropriate, excavated from the excavation end reverse regression on-time.
Gravel soil with picks before scarifying, mining, and depth of each layer,
depending on the thickness of the soil, and each layer and at the end of Qing
dynasty unearthed in and gradually dig.
3.3.2.2 shallow trench. Excavation of shallow
Strip foundations are basically the same, only Groove does not cut straight.
Elevation by Dragon door panel back down flat on the bottom, when digging close
to the elevation, and again from both ends on the bottom elevation of Dragon
door back to 50cm for the datum point, draw a small line with a ruler to check
the bottom elevation, finishing bottom.
3.3.2.3 slope excavation pits (Groove) and
when the trench should be according to the slope of the construction programme,
rough excavation, stratified according to the slope requirements make the grade
line of every 3rn, scoop with that subject line. When the deep trench digging,
in the Middle Groove width 80cm room at the dump.
3.3.2.4 when the excavation of Foundation
pit of large-area line, along the pit excavation of three sides at the same
time, dug from the earth-moving machinery-loaded into carts or dump trucks,
delivered by the excavation side not to give up the land.
3.4 excavation (Groove) or trench, close to
the underground water level, should be completed at the lowest elevation of the
excavation, and to concentrate in the water. After the excavation, dug out from
the tank bottom when 50cm, personnel should be compatible with the measuring
line out from the bottom 50cm flat cable from each Groove 20cm every 2~3M, in
small chunks of wood nailed on the trough level elevation. Digging at the time
near the bottom elevation, using a ruler or a prior measure 50cm feet, with
small chunks of wood at any time, check the bottom elevation. Finally by the
ends of the axis (centerline) Latrun line, check from the slot, slot width
criteria established, accordingly lift the trough and finally clear the bottom
Earth, end of raze.
3.5 pit (Groove) vertical and slope of the
trench, should prevent the landslide during the excavation process and open
and, if necessary, should be protected.
Slot when the soil in excavation, should
ensure the stability of the slope and vertical. When the soil is good, thrown
in the slot of the Earth (or materials) from the Groove (Groove) edge 0.8M,
height should not be more than l.5M. In the side columns, foundations or walls
around the base, no pile of dirt is too high.
3.6 excavation (slots) for earth moving, in
field conditions when stacked, must have sufficient backfill need good soil,
excess soil should be transported to the dump place, avoid second handling.
3.7 Earth excavation should not be
conducted during the rainy season. Or work surfaces should not be too large.
Should be segmented, piecewise completed in stages.
Excavation during the rainy season (Groove)
or when the trench, should pay attention to slope stability. If necessary,
appropriate slow slope or braces. While in the pits (Groove) outside surrounded
by Earthen berms or digging ditches, prevent surface water from entering. When
should strengthen, support, an embankment inspection on the slope.
3.8 excavation should not be in the winter.
If it is necessary at the time of construction in winter, its method of
construction should be carried out by winter programme.
To prevent freezing when the excavation of
earthwork, prior to freezing with insulating materials cover or soil tilling
raking, plowing depth shall be determined in accordance with local climatic
conditions, generally not less than 0.3M.
Excavation (Groove) or when a trench, you
must prevent the Foundation of Foundation soil subjected to freeze. Pit
(Groove) excavation has been completed, has a longer standing time, you should
set aside an appropriate thickness of basement elevation above soil, or cover
it with other insulation materials, the Foundation must not be allowed to
freeze. If the excavation Earth causes nearby buildings (structures) of ground
and Foundation exposed, antifreezing measures should be adopted to prevent
freezing damage.
4 quality criteria
4.1 project:
4.1.1 column base, pit, trench and trench
the soil must meet the design requirements of the base, and no disturbances.
4.2 allowable deviation, as shown in table
1-2.
Excavation, trench dimensions allowable
deviation table 1-2
Project tolerance (mm) test method
1
2
3 elevation
Length, width,
Slope on the steep +0-50
-0
Does not allow for level checking
Theodolite, cable and standard inspections
Observation or using a slope-scale
inspection
5 finished product protection
5.1 positioning axis standard pile, pile,
standard and standard, Dragon door, dug Earth without collision, or sat down to
rest on the Dragon door. And should always measure and checking its position,
level elevation and slope meets the design requirements. Positioning standard
benchmarks and standards, should also be repeated on a regular basis check that
they are correct.
5.2 when the excavation, should prevent the
adjacent to existing buildings or structures, roads, pipelines, such as
subsidence or deformation will occur. If necessary, the protective measures
taken in consultation with design or construction, and in the construction of
settlement and displacement observation.
5.3 If artifacts are found in the
construction or Tomb Raider, should be protected and should be immediately
reported to the local authorities after treatment before continuing
construction. If there are any permanent target for the measure or established
long-term geological and seismic observation points, and so on, should be
protected. Laying in the ground or underground pipe and cable location when
making earthwork, prior written consent of the relevant authorities,
construction should take measures to prevent damage to the pipeline.
6 quality problems to be noticed
6.1 basement overbreak: excavation (Groove)
or trench shall not exceed the base level. If the place when over, it should be
agreed by the design unit, not allowed to deal with.
6.2 digging pile in soft soil area to
prevent displacement of pile: when excavation in a compact group piles, pile
driving completed, interval, symmetric dig; in dense piles near the excavation
(Groove), be pre-identified pile displacement prevention measures.
6.3 basement unprotected: pit (Groove)
excavation should minimize the disturbance on the base. Basis as delays in
construction, 0.3M thick soil layer can be elevation above substrate, base when
removed.
6.4 construction order is unreasonable;
excavation first from the lower, staged excavation in turn, forming a certain
slope to facilitate drainage.
6.5 excavation dimensions: the pit (Groove)
width of the excavation or trench bottom, apart from the structural width,
should be based on the need to increase the Width of the construction. Such as
drainage, the width of the support structure required, in front of the
excavation shall be taken into account.
6.6 pit (Groove) or trench slope in
straight rough, uneven Base: checks should be strengthened, with the dig with,
and careful inspection.
7 quality records
This standard shall meet the following
quality records:
Engineering geology investigation report of
7.1.
7.2 project location records.
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