Waterside E P1-SP 920220 TRENCH SAFETY
SPECIFICATIONS
FOR
SANITARY SEWER
&
LATERAL REPAIR
to serve
WATERSIDE ESTATES PHASE I
CITY
OF
COPPELL, TEXAS
Prepared for:
S & S Utilities, Inc.
February 1992
S & S Utilities, Inc. File No. 9221
1.0 DESIGN ASSUMPTIONS
1.1 General. These specifications cover the basic requirements for shoring
and/or sloping of excavations for installation of Sanitary Sewer and Sanitary
Sewer Lateral Repair for the Waterside Estates Phase I Project, Coppell, Texas.
1.2 This specification addresses the safety of workers in a trench excavation
and does not, in any way relieve the Contractor of his responsibility and
liability to ensure the safety of the project and workers.
1.3 It is not the intent of these specifications to specify every detail and
procedure of the trenching/shoring operations; nevertheless, they shall
conform to the high standards of engineering and of safe trench
excavation.
1.4 The personnel protection systems shown in these specifications have
been designed based on information obtained from the project drawings.
1.5 The personnel protection systems shown in these specifications have
been designed based on an assumed subsurface of Type B Soils. In
accordance with Revised OSHA (effective March 2,1990), prior to
begining construction, The contractor's "Competent Person" will
conduct the required Soil Classification Tests. If soils other than those
identified are found, this specification will be revised. During
construction, the contractor's "Competent Person" will monitor the
soil classification as required by OSHA 1926.
1.6 Contractor shall be responsible for selecting appropriate safety
system option shown in these specifications depending on trench
depth and soil conditions.
1.7 The protection of existing structures and utilities which may be
affected by these trench excavations is beyond the scope of this report.
1.8 The Contractor must identify a "Competent Person" in the Contractor's
firm responsible for performing inspections of the excavations to
ensure that expected subsurface conditions are present. If conditions
in the field vary from the expected conditions,Noakes Engineering
Company shall be contacted at (817) 640-8930, for possible design
modifications prior to personnel entering the excavation. Note -This
person must be "Competent" as described in OSHA 1926.650 (b).
1.9 .It is the Contractor's responsibility to ensure that all excavation work
and site conditions are within the regulations as established by
O.S.H.A. Any property damage or bodily injury (including death)
arising from the use of these specifications, from Contractor's
negligence in performance of contract work, or from Owner's failure to
note exceptions to these specifications shall remain the sole
responsibility and liability of the contractor.
S & S Utilities, Inc. File No. 9221
2.0 DEFINITIONS
2.1 All definitions of section 1926.653 of Subpart P, Part 1926, of the Code of
Federal Regulations shall be by reference an integral part of this section.
2.2 "Sealing Engineer" - The engineer whose Texas seal is affixed to these
specifications.
2.3 "The Contractor" - The contractor responsible to the owner for the
excavation work described herein.
2.4 "Competent" as described in OSHA 1926.650 (b).
3.0 APPLICABLE CODES AND STANDARDS
3.1 The Contractor shall perform all shoring work under this contract in
accordance with all applicable codes and standard safety
requirements and regulations including:
3.1.1 OSHA 2207, Construction Industry Standards(part 1926
Occupational Safety and Health Standards)
3.1.2 AISC Code of Standard Practice
3.1.3AISC Specification of the design, fabrication, and
erection of steel buildings.
3.1.4AITC Timber Construction Manual
3.1.5AWS D1.1 Structural Welding Code
3.1.6The Uniform Building Code
3.1.7OSHA 2226
3.2 The latest edition (including supplements and revisions) of the above
publications in effect or promulgated at the time of the bid shall
apply. Equipment fabricated to codes and standards in effect at time of
bid but later revised shall be acceptable provided such revisions are
not required by law.
4.0 SHORING/SLOPING REQUIREMENTS
4.1Description. This section covers the technical requirements
of the trenching/shoring work.
4.2 Existing Structures.Where existing buildings, other utilities,streets,
highways, or other structures are in close proximity to the trench,or
may otherwise be affected by the proposed trenching operation, the
.Contractor shall provide adequate protection by the use of sheeting
and shoring to protect the structure,street,or highway from possible
damage. In the case of utilities, the Contractor may elect to remove the
utility provided that the removal and subsequent replacement meets
with the approval of the engineer, the utility owner,or whoever has
jurisdiction of the structure. In all cases, it shall be the responsibility of
the Contractor to protect public and private property and any person
or persons who might, as a result of the Contractor's work be injured.
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S & S U~ilities, Inc. File No. 9ZZ1
4.3 General Trenching and Shoring Requirements.The contractor
shall be solely responsible for trench safety provisions meeting
the applicable requirements of the United States Department of
Labor Occupational Safety and Health Administration including
subpart P,Part 1926 of the Code of Federal Regulations. All
trenching operations and procedure shall also conform to the
requirements listed in this specification.
4.3.1 The requirements of sections 1926.50 and 1926.651 of
Subpart P, Part 1926, of the Code of Federal Regulations
shall be by reference an integral part of this section.
4.4 Requirements Prior to Excavation Activities.
4.4.1 Known underground installations are shown on the site
plans. It is the Contractor's responsibility to verify exact
locations in the field.
4.4.2 Before any individual enters an excavation, the excavation
will be inspected by a "Competent Person" to ensure that
trench excavation has been performed according to this
specification and O.S.H.A. requirements and to ensure that
no anomalies are observed which may effect the safety of
the trench or project. Note -This person must be
"Competent" as described in OSHA 1926.65(b).
4.5 Requirements During Excavation Activities.
4.5.1 During excavation, the exact location of existing
underground installations shall be determined by the
Contractor, and when uncovered, proper precautions and
supports shall be provided so as not to cause a hazard to
the workmen or project.
4.5.2 Daily inspections of the excavations shall be made by the
Contractor's "Competent Person". If there is evidence of
possible cave-ins or slides, all work in the excavation shall
cease until the necessary precautions have been taken to
ensure the safety of the workmen and the trench.
Note -This person must be "Competent" as described in
OSHA 1926.650 (b).
4.5.3 Excavations shall be inspected after every rainstorm or
other hazard-increasing occurrence to ensure the safety of
the workmen and the trench.
3
S & S Utilities, Inc. File No. 9221
4.5.4 Excavated material shall be stockpiled a distance away
from the trench, so as not to affect the trench stability. The
contractor's construction means and methods will
determine the distance. As a minimum to protect the
workmen from falling debris, the toe of the stockpiled soil
shall be no closer than two (2) feet from the edge of the
excavation.
4.5.5 All precautions must be made to prevent surface water from
entering the trench excavation. Adequate drainage must be
provided in the area adjacent to the excavation.
4.5.6 Operation of heavy equipment adjacent to the edge of the
trench may cause instability. The Contractor is responsible
for the means and methods of excavation, and therefore, for
loads imposed on the trench excavation and shorin design.
4.5.7 The Contractor must take precautions to protect the face of
the excavation from exposure to excessive drying,water,or
freezing.
4.5.8 Water shall not be permitted to stand in the bottom of the
trench and suction pumps of adequate capacity shall be
installed to ensure that such standing water is removed.
4.5.9 The Contractor shall provide a positive means of ensuring
that hydrostatic pressure does not build up behind the
shoring or shields.
4.5.10 If a condition requiring the use of a different method of
shoring is encountered, this specification will be revised.
4.5.11 Remove shoring units from bottom to top as backfilling
proceeds.
4.5.12 When backfill is within five (5) feet of the top of the trench,
all shoring may be removed, unless the trench ~onditions
indicate a hazard.
4.5.13 No person shall be exposed to the lower portion of the
trench after shoring has been removed.
4.5.14 Additional shoring or larger sizes may be installed.
4.5.15 Ladders or other adequate means of exit must be provided
and located so as to require no more than 25 feet of lateral
travel.
4.5.16 When tWO trenches intersect,both trenches must be
protected to a distance of not less than the depth of the
deepest trench.
4
S & S Utilities, Inc. File No. 9221
4.6 Shoring Alternatives for this Work
4.6.1 Trenches more than 5 feet deep shall be shored, laid back to
a stable slope,or some other equivalent means of protection
shall be provided where employees may be exposed to
moving ground or cave-ins. Trenches less than 5 feet in
depth shall also be effectively protected when examination
of ground indicates hazardous ground movement may be-
expected. The contractor will have options for providing such
protection.
4.6.2 Lateral Earth Pressure
P= a uniformly distributed lateral soil pressure,in lbs./ft.2
We= Effective Soil Weight, pcf (Use 45 pcf Type B Soil )
H= depth of excavation from top of supported bank
to bottom of excavation,in feet.
Hq= Equivalent Height of Surcharge,ft.
P= We*(H+Hq)
(Reference OSHA Rules and Regulations-Part 1926 of 29
CFR as amended by the Federal Register Volume 54,Number
209, dated October 31,1 989.
Note: Since there is no geotechnical analysis, any ROCK encountered
on this project will be protected as Type 'B" Soil.
4.6.3 Option I The contractor can use Slope as shown in the
Option I section of this specification.See Drawing Option I.
4.6.4 Option II The contractor can use Trench Shield as shown in the
Option II section of this specification.
See Drawing Option II.
4.6.5 Option III The contractor can use Trench Shores as shown in the
Option III section of this specification.
See Drawing Option II1.
5.0 EXCAVATIONS SPECIFIC TO THIS WORK
Location Max. Depth Option(s) Notes
Sanit~ Sewer Line (Alternate)
Manhole In
Parkway Bird,
at Lakeshore Dr. 9.0 I,II or III Connect to esist. Manhole and install 8' SS
accross Parkway Blvd.
Various 9.0 I,II or III Expose exist. SS Lateral, repair or replace
as required (approx. 20 Locations.)
5
Trench Safety Specification
CASE I
2'-0" MIN.
( )
CASE I - ORDINARY SLOPE
CASE II - SLOPE WITH BENCH NOT GREATER THAN 3' - 6" HIGH-ALLOWED IN STIFF CLAYS OR ROCK ONLY
H/V= STEEPEST ALLOWABLE SIDESLOPE
H/V= I:1 IN STIFF CLAYS OR ROCK
H/V= I.S:I IN STIFF SILTY CLAYS
H/V= 2:1 IN SOFT LOOSE SOILS OR FILL MATERIAL
NOTE:
ALL SLOPES ASSUME DEWATERED SOIL CONDITIONS
ALL SLOPES ASSUME SUFFICIENT RIGHT OF WAY EXISTS
ALL SLOPES SHOULD BE FLATTENED AN ADDITIONAL 0.S:I IF AN EXISTING PARALLEL UTILITY LINE IS LOCATED
WITHIN A HORIZONTAL DISTANCE EQUAL TO THE DEPTH OF THE NEW UTILITY EXCAVATION.
CONTRACTOR'S "COMPETENT PERSON "TO EVALUATE SUBSURFACE CONDITIONS AND DETERMINE SOIL TYPE
AND CONDITION.*
NO SPOIL OR EQUIPMENT NEARER THAN 2.0 FT. TO EDGE OF EXCAVATION.
EXPOSED EXISTING LINES TO BE SUPPORTED IN A MANNER APPROVED BY PROJECT MANAGEMENT.
* WHEN CONTRACTOR'S "COMPETENT PERSON "CANNOT ASSURE THAT THE SLOPE IS
SUITABLE FOR SAFE USE, NOAKES ENGINEERING COMPANY OR A QUAUFIED GEOTECHNICAL
ENGINEER SHOULD BE CONSULTED.
~. ED D, NOAKES
REGISTERED pROFESSIONAL ENGINEER. DATE I,x'~,'o.~'/S"~.'~.¥.."._~..~' SLOPE
Noakes Engin. c"~i_ 'ng Company File No. 9221
GENERAL NOTES:
I. A 'Trench S~IC~' is · structure this normally will not prevent · Cay·e·, bat is ·bio to wKhstand the for~es imposed on K by · Cave-in ·nd thereby p~otect empioye~ withbt siva structural Tr~¢h ~iold· tn
lbo commonly referred e0 ss ' Trench Boxes'.
2. A 'Pre-menufi~Jred shidd ' b I product des·In·d, con~'ucted lecl rn~c~d to the toe·traction ·acius·fl ·· · method of pro~ec[inj personnel whi&e w~ri6n~ in trenches subjec~ te cave-ins.
3. A ~hop-buik I~aiekl · is d~ined heC~n Is · s~ioid bulk by I con·retry- ac hi· ·lent fac they o~n use 1· I pacsaanel prO~'~on device ·ed is not i~llble CCetmle~cially si · p~-oduct to the toe.ruction
4. ACCE~q'ABLE SHIELD SYSTEMS
Oevis~ons from the manufacturer's speciRca~Jons, rec~nmendmons ·nd he~ka%loas will not be ~lJowed uflJess the miaul~cturer is·ecs qaecJf~c wri~en ipp~eL This spas. irK wrKeen Ipprc~l of clevis·ions
S. Sbop.baik Iii·ids m~y be used when desillned ·nd senled by s professional ertl·neet rqistered in the State of Tex~s bavin~ I back&roued in the prac~ce of structural
&. ~ie~Js shill be h ~ d~ma~ or de~ec~ this might ~laiir ~ p~oper ~uncl~on. Shields th&l~ be u~ucI Ind maintained in · rrmnner cons~steei: widl tim rec~mmenc~tions of
en~neac. I:)u~lecl eduipm~nc shill be rffnoved from Nrvic~ until ·u~her~zed rep~ln sm mid&
7. ·hie&ds shill be ·rd·ailed in · rni#.er which res~.r~s literal ac ocher hecardous moveenent of ~e shield in the event of the ij)plicirdOl Of sudcbtll ~-terll ~oids. Where ·Bach shieids ·re s~chesL · macbanism
must be Iv~liihbt for connac~ng the shiekl~ to prevent dWerectiit movement between the sh~ed when subject to Iscar~l Jozds. GenchinI o! esrth miterisl below ch bo·tern of the shidd ts ill~wed to ·
max~vm o~ 2.0 f~, when this benched miami is of suf~lent stmn~ te suppc~ dm
te s p~tentll! cay·dh h~rd dudnI en~ or mdc Irom ~e sh~d.
9. Shields Shell be used such that exca~d mil r~k or o~er dd~s can not f~ll or rQII bt· the ~rench $hiekL in vertis~ trenches the shield zho~k~ r;ee · minb~lurn o! I' -6'
sz~u·cions where I silo· is cons~ruc~d ibove the top o/the shield, ~e top of the shiekll should ex.nd · mlnm~um of 1'-6' ·boy· the point ·c which the sl~e begins. In ·dcIkion the Con,racer thrall be
req)onsibic lot removal c~ sell whlr~ may s~lh iago the treesh or sll:~ ~he u~nch ihleld Md Jot repbKinI these m~erills in ·ccordlnto wi~ the bscldill speciRca~)n~
A A
....... ,,~, / .."..'."..'.' ,/ ./
" H
:,, ,, ,~: ,"~ ,,,,,,,,,, ........ . ;>,,,,,,,~, ......... ,,
:, ~ ,, ~. ~ H ~: ~ ,. ,
~ ., ~, ~ H
CASE I ~ ~ / ....
SPECIAL NOTES:
~SG I - T~nch Shield e~endin~ a~ve exca~on C~E 4
~SE 2 - Tren~ Shield on ben~, top of shield e~endin8 a~ve excavadon A = ~I~U~ 1.0 ~.
B= N~INUN ~.0 FT. IN STIFF SOIL ONLY
~ASE 3 - Trench Shield ~ slope it ~p ~= NININUN 1.5 ~.
~SE 4 - Trench Shield on bench ~ slope at ~p hlv = ~EEPEST ALLOWABLE SLOPE
hl~ I:1 THIS PKOJE~T
Trench Shie~ mu~ have minimum lateral beadng capaci~ as follows:
525 PSF- ~PE "B" SOIL
CONTRACTOR'S "COMPETENT PERSON" SHALL CLASSIFY SOIL TYPE AND DETERMINE REQUIRED TRENCH SHIELD CAPACITY.
CONTRACTOR SHALL MAKE AVAILABLE MANUFACTURER'S TABULATED DATA OR CAPACITY CERTIFICATION FOR ALL TRENCH
SHIELDS USED ON THIS PROJECT.
.. ............................... :....~ OPTION II
~-o-~ '~'~ ~,~2"..~., 24752 ,q ..,";~ TRENCH SHIELD
Noakes Enginee~ng Company File No. 9221
I.'Aluminum Hydriulic Shorl~' a~ B p~u~ ~ I~ ~n~tu~ u in I~ ~ c~ shoal In o~ ~ ~ B I~h~kc p~uG c~b ol ~i~ in~ and r~
Z N~in~ Hy~u~ S~m sh~l h ~ and ~nu~ ~ ~ ~ ~ w~ OSHA ~l~ns i~ pmv~ ~ of ~e v~l nil and h~ul~ ~1~ cms~ ~h
~ The ~k ~r c~ s~ ~ ~ 2- i~ LD. e~ ~ d smumbg in ~ ~e of ~K ~ ~ln ~,~ ~u~ it I I~O n~ h~ ~ 50 ~ ~sbn.
3. Th v~J ~b, h~u~ c~ c~ I~ ill o~er c~M~ of &e ~ ihlE ~ in g~ ~ c~n and w~t &~p or ~ wh~h ~u~ pmhbk p~
4. ~. ~ in ~ni~n ~ ~nul~ ~ I~il ~ ~ ~b8
b. Hi~ ~ muK ~ ~4'. m~um ~ ~ B~h p~ 'FInnFo~~ bn~ or ~vl~ I~lll h~
~ whKh b ~ ~ ~ or ~ ~ I~ uMu~ ~ ~ I~ pu~ shall ~
S. ~. C~tn~r sbu hGil ii.bum h~ul~ ~om in ;~*nfl wM ~m I~m~t~ and ~ mlnuhRu~s ~i~ b~ ~~ Ifld I~
p~n shill hsu~ ~ ~e wo~ i~ll~& ~v~8 Ind wo~ I~und ~l sho~ hlvi ~ Id~l~ t~in~ in ~ ~ ~ ~r ~ir b~h~ofl, Slh uN Ifld ~L
~ th~ h p~md ~ I HmJ K~ n~ of 7~ ~ I ~ p~
7. ~ Con~r tomy e~ hb di~n ~ll~e sho~r Y~ll ~lll in ~r ~ 8cc~ ~oH s~tions such ms bec~lfl~ wh~ c~ ~ch ~h ~ m shilbw I~ uN
9. ~ Contour ~y ~ his ~tm~ ~ ~ve s~ng ~ ~ ~e in~ibt~ ol ~ p~ ~t w~ I~ ~t ~ ~ t~ uns~ ~h m~ p~i~
MAX. MATERIAL
,L ~ '~ "/ PLYVVOOD BACKING
~ (VVhen Required)
I ]
9'-0' MAJ~ "
1 r , -.-,,-
I'- 6 "MAX. MAXIMUM ALLOWABLE HORIZONTAL SPACING = S.0 FT.
"SPEED-SHORE" TM, · .!,~~l~ · TM OR APPROVED EQUAL
................................ ,.
~.;~:..,..?..?.....~.?~.~.~..s....:~,~_ TR£NCH SHORES
~ ~. 24752
~t O::.'~x~_ _¢_~.'"."~.. NOT TO SCALE
REGISTERED PROFI ;IONAL ENGINEER DATE ~,;~":'~'/$TC..,?-'5,:'~,?.*
'1Y,S' ................ -:~ -..-
Noak~ Engineering Company ~,~.~.,,~::ti~N~. 9221