ST9905-CS050912~..Su~a~ n"T~ytor~i: RE: Be~el R~ad Drainage
<ccbondg~transystems.com>
<staylor~ci.coppell.tx.us>
9/12/2005 2:27:52 PM
RE: Bethel Road Drainage
c q. 0.5
Joe Mestemon in our Fort Worth office is going to send me the current
'%'Vage Rates" they use for their Fort Worth projects. I'll fonvard the
document when it arrives.
Also, I went through the box culvert section in the geotech report. The
only backfill requirements they really have am for wall backfill
material, but the cement treated backfill proposed in the specifications
should meet or exceed the geotech report recommendations, so it should
be ok as is. I have included pdfs of the geotech report pages for
crag
Original Message ....
From: Suzan Taylor [mailto:staylor{~ci.coppell.tx.us]
Sent: Monday, September 12, 2005 10:19 AM
To: DL-Chades Bond
Subject: Bethel Road Drainage
Craig:
,Mta~hed are the specifications, I have added the bid numbers and dates.
Our %'Vage Rates' is ou~lated - do you have a mom recent version that
can be used? I will have to provide the 'Notice to Bidders' to
purchasing tomorrow.
I have included a technical spec for the cement treated base - please
verify the class that is shown in the pay item description. Also, did
you ~heck to see if anything was required under the box culverts besides
the compaction.
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EQUIVN. ENT FLUID PRE8SURE$
t ,. n~ :~- 'i ' i I'
' SeM~ fkl, wlth Liquid Umit leas than 35 and
P essthan 15 65
Granular ba~Hill with le~ than 3% p~saing
Sundlarge Ioad~ ~houtd be included in the wall deign where ai~xoprlate. A lateral pressure
~oe~k~ent o~ 0.5 is recommended for uniformly dlstdb~ed surcharge loads. A unit weight of 135
PCFie recommended for b~ml~ll over the culvert.
Wall ~ matm~l~ ~'toutd be placed In Iooee lift~, less than 9 inches thick, a~ ~o~y
~~a~~~~O~.
~~ ~ ~ ~,~ 0 ~ +5 ~e ~ ~e~
~m~~lnt~A~M D~. G~r~la~ ~t~
~.~ ~ ~ ~ ~ ~ ~ ~ at a ~re ~t to a~ ~e
pavement distr--.
Trallle 8kalM Fo~inda&~
Inteme~ton traffic ,~tgrtals are planned in the areaa of Borings R-7 and R-14. In
designed for lateral sul:~x~. Design paramelers for straight drilled shaft foundations are discussed
below.
Straight dn~ed, reinforced cortcrete shafts should be situated at a minimum depth of 8 feet be~w
existing grades. The straight shaft~ may be proportioned using an allowable bearing pressure of
2,000 pounds per ecl[mm feet (PSi=).
9403~316 - 9 -
The days ef~ountered along the alignment are moderately a~tive to highly active and subject to
volume changes with fluctuation~ in their moisture content. The clays expand (heave) with
increasas in moieture and oontract (ehrtnk) with deoreaass in moisture. The movement at the
(=enter cd the pavement ty~ oceura as po~t onnstm~lon heeve. At the edge of the pavement,
both ~hrinklge and swell could oncur due to seasonal moisture fluctuations in response to rainfall
and evapotfin~plration.
The potential magnitude of the moisture induced movements is rather indeterminate. It is
influenced by the .ofl properties, surface drainage, overburden preasuras and to a great extent by
soil moisture levels at the time cd conatmctton. The greatest potential for post-oonstruction
movement ocoum when the sugs are in dry condition at the time of oonatmction. Based on
TxDOT Telt Method 124-E, potential active ~ofl movement8 along the alignment are setimated to
varyfrom about 1½ to3inches. Larger movemente could o(;cur In sume ieolated areas.
Flat grades ehould be avoided with poeltive drainage provided away from the pavement edges.
A mlrdmum grade cd 0.5% and profemifly 1% hi ~ for all pavements.
Three 5X10 bricige-de~m ~ box oulvert~ are ptanned naar tbe ea~em limits of the project.
Baaed on the =onditione encountered in the brxtng near the ~ ~truotures (Boring R-15),
ex~avatlon~ will eneoum~ (days, candy c4aya asnde and ellty days beneath the exl~ing
pavement ey~tem and gravel f#1. Thas~ ~ must be ~ or braced in the interest of eafe4ny.
O.$.H.A stendard~ for Isra~qg ~m~M:Vor beoke4o~ ahou~l be fo#owed. The following dasign
A maudmum aflowabie bearing preeeure ol 1,600 PSF Is re~ for design cd structore~
founded In the natural day, aencly clay, silty day and sand soil~.
The lateral prassum eOpropdate for the dastgn cd the culvert and wing walls wifl be a funofion cd
the bacld#l material and the magnitude cd any surcharge Ioacle acting on the backfill. The lateral
pressuras presented are for an &t-mat earth condition, which means that the below-grade ~
are assumed to be rather rigid and v~y little, if any, deflection of the walls will occur. They
94035316 - 8 -