Page 17 - Arkansas 811 Magazine 2018 Issue 2

CONTINUED FROM pass 13 g

ONION x17 sl.oEINc AND EENCHING ,

Thi. procedure calls, iirst, tor clas.iiying the soil, then reterring to the charts 4.. .;, '

and illustrations in the OsHA standard to determine the correct angle ui the " ' A j
.loping or benching . '

From the OSHA standard _f , “

TypeSoi| Angle ofBarIk I ii 5-_
t—.» t, , ., g .
Stable Rock Vertical wall ~o ‘g, '
Type ASoi| 3/no 1 (H to V), or 53 degrees V "'3'
Type B Soil 1 to 1 (H to V), or 45 degrees
Type C Soil 1 ‘/2 to 1 (H to V), or 34 degrees __ ;_\_
. , , , .

ONION :2 7 TLMEER SHORINC. . _

Tlii. is a systern or wooden walers, cros. braces and uprights that .upport " ' "_ V‘ J ' a -

the walls of a trench or nxcilvatlnn. The OS!-LA standard .peciae. the " " , \.. .
.ize. of timbers, ba.ed on the various type. of soil, the depth of the trench .

or excavation and the type of timber u.ed to build the structure (oak or

Douglas i’-tr) .

ONION #3 7ALuMINuIvI HYDRAULIC SHORINC , _ — ’ ‘
Hydraulic slioi-ing .y.tems have replaced a lot of timber .horing. Developed cw’ * V

in calitornia in the late 1950s, there are two main type. of hydraulic .horing . ‘ _
.ystems vertical .hore. and horizontal waler.. both employ aluminum 7 Jfi 4‘

rails and hydraulic cylinder. that apply pre.sure to the wall. of a trench, . , W

creating an "ilrchlng effect” in the ad,acent .oil that prevents the wall. trorn ' t ,

collap.ing. e /

ONION x4 7 TRENCH SHIELDS

Trench shields are aluminum or .teel structures designed to protect worker.

by with.tanding the torees of a cavein Regardless of the rnatenal they are

made of, the principle. tor trench shields are the same.

ONION #5 7 SITE-SPECIFIC ENGINEERED SYSTENB

Orcmionally the chart‘ In the OSHA Standard for slaving and bend-insr 4 aert Ni‘m‘7A oarsuv..r.- vraarr may to Mt‘ Dtwctlltttulll to
or timber .hormg, as well rnanutactured .y.tems such as aluminum }YVAlI£'4‘IYA.V)W(W‘<HILTVMW(‘ALYl1NlMW$VNAflM)H€
hydraulic shoring or trench .hield., are not appropriate. There may be

lubsltz conditions or other tactors that prevent the use of all these .y.tems

In these .ituatioiis, a registered protes.ional engineer rnust design a system T S . _

.pecifically tor the ]nb. The engineer ha. to be regi.tered in the state where “ “‘“'“‘““"

the system will be used and will have to "stamp" the design There are By having a properly trained and authorized
addllional requirement. a. well, all of which are covered in the OSHA competent Eenon on.ite and following
standard the General I<equirernent. section or the
Slap #5 _ mspm we Emmi“ OSHA Stnndr1rd,carcfully classitying the

.oil, then by uhhzlng protective .y.tems and

The properly trained and autlionzed Competent Person must in.pect rigorously and repeatedly in.pectmg every
excavation. daily tor excavation, you and your employees can

_ mdmim of Pwible m2_im; work satcly in trenches and excavations. .
- tailure of protective systems;

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- or other hazardous conditions. Erptipvicrit, LLC whit-h proridcs aalca, rmml

eqaiptttcnl, rcpatr SCVI/ICE, and an/cry lmtitmg to

Inspection. rnu.t be conducted prior to the start of work and al.o as needed mlmmmw ammo“ M mm mm M.”
throughout each .hirt, atter rainstorm. and atter other potential hazard. W, W“, T',mhs,,,C,’ M, 0, my“, ‘’ ‘
increa.ing events The Competent Person must also check adlilcenl areas and um,,,_,,.,,U,,,,,,s,,,W' mi, '
protective .y.terns (before and during use) and look always tor indications ‘ ' '

of po.sible cave-ins and hazardous or potentially hazardou. conditions. 2013 MM WM an MW” , ,5