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<br /> OCCUP A TI 0 N A L ,SAn:TY A ND REAL TH 1926.651(1'\
<br /> STANDARDS AND INTERP1tE-rAT10NS
<br /> and design of the supporting system shall be Cj) Sides, slopes, and faces of all excavations
<br /> based on careful ,evaluation of pertinent tac- shaH meet accepted engineerinJr require-
<br /> tors such as: Depth or cut; possible variation ments by scaHng, benching, barricadinJr. rock
<br /> in water content of the material while the bolting, wire meshing, or other equally eft'ec-
<br /> excavation is open; antic:ípated changes in tive means. Special attention shall be lriven to
<br /> materials from exposure to air, sun, water, or slopes which may be adversely atf'ected by
<br /> freezing; loading imposed by structures, weather or moisture content.
<br /> equipment, overlying material, or stored ma.
<br /> terial; and vibration from equipment, blast. (Ir) Support systems shall be planned and
<br /> ing, traffic, or other sources. designed by a qualified person when excava.
<br /> tion is in excess of 20 feet in depth, adjacent
<br /> (f) Supporting systems; i.e., piling, cribbing, to structures or improvements, or subject to
<br /> shoring, etc., shall be designed by a qualified vibration or ground water.
<br /> person and meet accepted engineering re-
<br /> quirements. When tie rods are used to re- (I) Materials use for sheeting, sheet piling,
<br /> strain the top of sheeting or other retaining cribbing, bracing, shoring, and underpinning
<br /> systems, the rods shall be securely anchored shall be in ~ serviceable condition, and
<br /> well back of the angle of repose. When tight timbers shall be sound, free from large or
<br /> sheeting or sheet piling is used, full loading loose knots, and of proper dimensions.
<br /> due to ground water table shall be assumed,
<br /> unless prevented by weep holes or drains (m) Special precautions shall be taken in
<br /> or other means. Additional strin$rerl, ties, sloping or shoring the sides of excavations
<br /> and bracing shall be provided to allow for any
<br /> necessary temporary removal of individual adjacent to a previously backfilled excavation
<br /> or a fill, particularly when the separation is
<br /> supports. leal than the depth of the excavation. Partie.
<br /> (g) All slopes shall be excavated to at least ular attention alia shall be paid to joints and
<br /> seams of material comprisin~ a face and the
<br /> the anJrle of repose except for areas where slope of such seams and joints.
<br /> solid rock allows for line drilling or pre-
<br /> splitting.
<br /> (n)Except in hard rock, excavations below the
<br /> (h) The angle of "})Ose shall be ftattened level of the base of footing of any foundation
<br /> when an excavation has water conditions, or retaining wall shall not be permitted, un-
<br /> silty materials, loose boulders, and areas less the wall is underpinned and all other pre-
<br /> where erosion, deep frost action, and slide cautions taken to insure the stability of the
<br /> planes appear. adjacent walls for the protection of employees
<br /> involved in excavation work or in the vicinity
<br /> thereof.
<br /> (i)
<br /> (0. If the stability of adjoininJr buildings or
<br /> (1) In excavation. which employees may walls is endangered by excavations, shoring,
<br /> be requ:red to enter, excavated or other bracin~, or underpinninll.' shall be provided as
<br /> material shall be etfeetively stored and reo necessary to insure their safety. Such shor-
<br /> tained at least 2 feet or more from the edge ¡ng, bracing, or underpinning shall be in-
<br /> of the excavation. spected daily or more otten, as conditions
<br /> warrant, by a competent person and the pro-
<br /> (2) As an alternative to the clearance pre-- tection effectively maintained.
<br /> scribed in subparagraph (1) of this para.
<br /> graph, the employer may use effective (p) Diversion ditches, dikes, or other suitable
<br /> barriers or other effective retaining devices means shall be used to prevent surface water
<br /> in lieu thereof in order to prevent exea- from entering an excavation and to provide
<br /> vated or other materials from falling into adequate drainage of the area adjacent to the
<br /> the excavation. excavation. Water shall not be allowed to
<br /> 181 I9Z6.65l(p}
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