SABS 1200 DN-1982
Earthworks (railway sidings)
CONSTRUCTION
PRECAUTIONS
Safety. The requirements of Subclausc 5.1.1 of SABS 1200 D or Subclause 5.1.1 of SAnS 1200 DA, as
relevant, shall apply.
Stormwater and Groundwater and D u s t Nuisance. The requirements of Subclauses 5.1.3 and 5.1.4 of SABS
1200 U or Subclauses 5.1.4 and 5.1.5 of SARS 1200 DA, as relevant, shall apply.
METHODS AND PROCEDURES
Excavation
General
a) G. After completion to the extent necessary for excavation of site clearing i n terms of SAS ~ Z O Oc
and, i f required, a f t e r topsoil has been dealt with i n terms of SAW 1200 U or SA65 1200 DA, as
applicable, c u t s shall be made and finished o f f neatly to the s:tde slopes, widths, levels, grades, and
sections shown oil the drawings or ordered. The finished formalion width shall be at l e a s t t h a t shown in
Drawiny DN-1 appropriate t o the layout.
The slopes of cuttirigs shall not be trinuned t o a smooth surfacc but l e f t as cut by bulldozer or scraper
to provide ledges to r e t a i n topsoil.
Any overbreak s h a l l be made up a t the Contractor's expense with b a c k f i l l or concrete blinding or rock as
directed.
Borrow p i t s shall be so developed as to minimize the danger of s o i l erosion, and s h a l l be graded and
drained and the material used as directed. On completion of the borrowiiiy and f i n a l grading and sloping
of the sides of the borrow p i t , the topsoil that was originally removed s h a l l , unless otherwise directed,
be spread evenly over the e n t i r e surface and side slopes of the borrow p i t .
b) Foundations for structures. The requirements for excavations for foundations of Subclause 5.2.2.1 of
SARS 1200' D or Subclause 5.2.2 of SABS 1200 DA, as relevant, s h a l l apply.
Use of material. The Contractor s h a l l not borrow, spoil, consei:ve, or waste any material without
approval.
material occurriny in cuttinys.
for the designed settlement t o take place. A l l materials excavated shall be deposited i n f i l l s unless
otherwise directed.
Topsoil shall be stockpiled and preserved for l a t e r use or shal:, be hauled directly t o areas requiring
topsoiling i f required i n terms of the project specification and scheduled.
Shallow cuts a r d f i l l s of depth up t o 300 mm.
acceptable, the top 200 mm or such other depth as may be directed s h a l l be compacted to the density
specified for the subballast layer of embankments and finished to the correct level.
Unsuitable s o i l below formation level s h a l l be removed by excavntion t o depths, widths, and lengths as
directed to permit the placing and compacting to the specified density of backfill.
Rock shall be removed to a depth below the finished level of 200 mm or such other depth as may be
directed, and replaced by approved compacted material.
Fills,
Preparatkn
a) Clearing site. Shrubs, bush, stumps, and debris shall be removed completely from the right of way for
the siding. Boulders shall be removed t o the extent required i n terms of the project specification. A l l
trees within 5 in of the formation shall be uprooted and similarly removed. The Contractor shall dispose
of a l l cleared material t o designated sites.
b) Suitable i n - s i t u material. Where the i n - s i t u material at the base of f i l l s is acceptable and the
Engineer requires that the base be consolidated, the top 150 mm or such other depth as may be directed
s h a l l , a f t e r the area has bee11 cleared as specified in (a) above, be compacted a t OMC to a density of a t
l e a s t 93 % or 95 % of modificd AASHTO maximum density as directed.
c) Unsuitable in-situ material. Unsuitable in-situ material a t the base of f i l l s or i n the floor of
cuttings shall be removed by excavating to such depths, widths, and lengths as are directed, to allow for
the placing and compaction of approved material a f t e r the top 150 mm of the s o i l l e f t i n place has been
compacted a t OMC to a density of a t l e a s t 93 % or 95 % of modified MSHTO maximum density as directed.
d) Renching. On ground with a slope yreater than one v e r t i c a l to six horizontal and on the sides of
existing embankments that are to be widened, the surface shall be benched as directed.
e) Catchwater drains. Catchwater drains or mounds (or both) to the dimensions shown on the d e t a i l
drawings shall be constructed not less than 5 m from the top of the b a t t e r of a l l c u t s and elsewhere as
directed.
Placinq
a) General. Of the material obtained from cuts and borrow p i t s only material that is free from stumps,
trees, rubbish, and other deleterious material and is approved hy the Engineer shall be placed i n the
lower layers of the f i l l and material of the same or b e t t e r qual.ity shall be placed i n the upper portion
of the f i l l . (See Subclause 3.2.1 of SABS 1200 D or Subclause 3.2.1 of SABS 1200 UA, as applicable.)
Where it is necessary to use clay or clayey material, the Enginc?er may d i r e c t that such material be
placed within not less than 1 m of the finished surface and not more than 6 m below it.
Rock having a maximum dimension exceeding 600 mm s h a l l not be placed a t the base of the f i l l .
Throughout the work the f i l l shall be constructed t o advance uniformly over the whole width with a s l i g h t
crossfall over the surface for drainage. The Contractor shall arrange iris operations so t h a t each layer
of f i l l can be compacted in suitable continuous sections which, unless otherwise agreed by the Engineer,
shall be of the greatest length practicable.
The f i l l material shall be deposited i n layers of thickness, before compacting, not exceeding 300 mm.
The materials shall be spread and mixed to form a layer of approximately uniformly graded material over
the whole width of the f i l l . Oversize (exceeding 300 mm) mater;.al t h a t cannot be broken down to the
maximum permissible size specified s h a l l be removed and used as directed. Each layer shall be watered
and compacted to the specified density. During compaction, every layer s h a l l be maintained to the
required slope and cross-section by means of self-propelled graders, and all holes and depressions shall
he f i l l e d with approved material.
The Contractor s h a l l ensure that stormwater w i l l at a l l t i m e s be discharged uniformly over the f u l l
length of each embankment or through down-lets.
--- --
--
The order of constructing the f i l l s s h a l l be so arranged as t o make the best possible use of
P r i o r i t y s h a l l be given to the construction of high f i l l s to allow time
Material surplus to requirements shall be placed on designated disposal sites.
Where the i n - s i t u material at formation level is
-
具体请见PDF 原件下载： 
|
