|
�
<br /> ;
<br /> TABLE 9. Approximate maximum backfill loads (in Ib. per lin. ft.) on concrete trench conduits*
<br /> Saturated top soil(K�,=0.150 and w- 110 Ib./cu.ft.)
<br /> Width o(trench at top ol conduit(in feeQ" �
<br /> Ht I
<br /> 2 3 4 5 6 7 8 9 10
<br /> 4 600 1,100 1,500 2,000 2,400 2,800 3,200 3,60� 4,000
<br /> 6 900 1,500 2,100 2,800 3,500 4,100 4,i00 5,400 6,000
<br /> 8 1,000 1,800 2,600 3,500 4,300 5,300 6,200 7,000 7,900 i
<br /> 10 1,100 2,lOD 3,100 4,100 5,200 6,300 7,300 8,400 9,600
<br /> 12 1,200 2,300 3,500 4,800 6,000 7,300 8,500 9,800 11,100 �
<br /> 14 1,300 2,500 3,800 5,300 6,700 8,100 9,600 I1,100 12,600 .
<br /> 16 1,300 2,600 4,100 5,700 7,300 9,000 10,600 12,300 14,000 -
<br /> 16 1,300 2,700 4,400 6,100 7,900 9,700 11,600 13,400 15,400
<br /> 20 1,400 2,800 4,600 6,500 8,500 iG,500 12,500 14,600 16,670 ,
<br /> 25 1,400 3,000 5,000 7,200 9,500 11,300 14,400 17,100 19,6G0 �,
<br /> 30 1,400 3,100 5,300 7,700 ]0,400 1'�,200 16,000 19,100 22,000
<br /> •By the Marston formula W�=CdwBa;surlace loatls not IncluEed.
<br /> •�Where width ol trench exceeds lhe transition wjdth�or lhe inslallation,lhe transition wi0lh shall govem(see page 31).
<br /> }H=Eepth ot�ill to top ol tontluit(in tt.).
<br /> TABLE 10. Approximate maximum backfill luads (in Ib. per lin. ft.)on concretetrench conduits•
<br /> Granular materials without cohesion (Kµ=0.1924 and w= 100 Ib./cu.ftJ
<br /> �o�������
<br /> Ht Widih o(trench at top o!conduit(in feet)'•
<br /> 2 3 4 5 6 7 8 � 9 10
<br /> 4 500 900 1,300 1,700 Z,SCO 2,500 2,900 3,200 3,600
<br /> 6 700 1,200 ],800 2,q00 2,900 3,500 4,300 4,700 5,300
<br /> 8 800 1,500 2,200 2,900 3,700 4,400 5,200 6,000 G,800 i
<br /> 30 900 1,600 2,500 3,400 4,400 5,300 6.200 7,200 6,200 i
<br /> 12 900 1,800 2,800 3,800 4,900 6,000 7,200 8,300 9,700 I
<br /> 14 900 1,900 3,000 4,200 5,500 6,700 B4O00 9,300 10,E00 �
<br /> 16 1,000 2,000 3,200 4,500 6,000 7.400 8,800 10,300 11,700 ,
<br /> 18 1,000 2,100 3,400 4,800 6,300 8,000 9,600 11,200 12,800 .
<br /> 20 1,000 2,300 3,500 5,000 6,700 6.400 30,200 12,OJ0 i3,800
<br /> 25 1,000 2,200 3,800 5,500 7,400 9,300 11,600 13,700 1b,000
<br /> 30 1,000 2.300 3,900 5,900 8,000 10,200 12,600 15,100 17,700 �
<br /> �By ihe Marston lormula W,_CewBJ:5urlace loatls not includeE.
<br /> �'Whcre�aitllh ol irenth eKceeAs ihe transition witlth lor the installation,the�ransilion wialh shall govem(see page 31).
<br /> }H=tlepth of fill to top ot condui�(in iL).
<br /> A� = 1 fIlC�Of L}lIIL 1S A fUI1C�1011 �((]ISfP1I)Uf1011 oI `���ICO �lic lnnd and reaction F,IIilIl�l0I1 CfftISC QIC �iPC
<br /> vcrlicnl load and vrrtical mnctiun and, tu erark fir,t at thc top (u�unll}� the ca�e n•hcn thc pipe �i
<br /> ihereforc, varies �cith thr class o( brddin{; is hrdded in a concrrte rrndlr), calucs o( .r' vii�tdd 6e
<br /> (,�r 1'nblc 13) �ub.li�ufrd for a in ihc• lond (ac�tor �ormiila.
<br /> :r = n factor that is a fun�tion uf thc ama nf 7'ablc 15 �ho�cs calucs of �h� load fuc�or for Ihc four
<br /> thr verlical projectim� nf Uir cuuduit on classes uf brdrlin� (or a fixed ��;iluc ot Ii, carious ratius �
<br /> �cLich the active lateral prnssnrr of tLr (ill of h��iqh� of ��mbaukment o:��r the pipr lo e�ternal
<br /> nui�rrinl act5 (se�� 1'uble H) bmudth of thr enndeit, :md (nr carinu, prnjectiou and
<br /> y = ihc ratin of ihe laterul pm„ure fo Ihc t�cr- setllrtnrnt ra�inn. It �cill bc notcd ih�t there is not
<br /> tieal pn:�sum, espressed b�• the furmula mucii difTrn•ure in thi� lond (a�•lur n•I�on ihr u�ttlrmcut ��
<br /> pR, rntin ;:n = 0? or �chru r.e = 0.7. 7'hreciorc, t•ulurs of
<br /> �II -F ,-� � �c1i�13� ��li U p �'�,i brt�cmu U.° nnd O.i ��nn hr detcrmiw�d fur all
<br /> �� C,tali� ('� �8� + .-��' l�rurtii�ul purpu�cs bc iiderpulatiun, und Lc}�und O.i
<br /> 35
<br /> �
<br />
|