Laserfiche WebLink
Crossing operation requirements under the appropriate method used and <br />subsurface conditions are as follows: <br />1) Driving or jacking, without auger - For casings with outside <br />1 diameters of three (3) inches or less, at the minimum depth of 36 <br />inches and up to five (5) inches outside diameter for depths of <br />cover exceeding six (6) feet, closed end jacking or driving is <br />' permitted. <br />2) Hydraulic or mechanical jacking, with auger - The use of an auger <br />' is required by the Department on all crossings using casings <br />greater than five (5) inches outside diameter (greater than three (3) <br />inches outside diameter if less than six (6) feet deep) and is <br />' intended to prevent a rigid plug of spoil material from forming at <br />the head of the casing. <br />If a drilling fluid is used to lubricate the outside of the casing, or <br />the auger and cuttings, it shall not be pumped under pressure <br />great enough to cause any jetting action whatsoever, or to <br />otherwise saturate the soil ahead of the casing. External drilling <br />fluid carriers shall be no larger than 3/4 O.D. and must be <br />permanently and securely fastened to the casing with the leading <br />end shielded from damage. <br />In soils with a high clay content only, plain water may be used to <br />clean the augers as necessary to prevent binding. When plain <br />water is used, it must be hand pumped or gravity fed through a <br />carrier pipe permanently and securely fastened to the casing. <br />G. Equipment Breakdowns or Other Unforeseen Stoppages <br />If forward motion of the casing is halted at any time other than for <br />reasons planned for in advance (addition of casing and auger sections, <br />etc.) and prevention of voids under paved areas cannot be assured, the <br />casing must be filled with concrete by pressure grouting as soon as <br />possible and abandoned. If removal of the augers from a casing to be <br />abandoned will allow voids to form under paved areas at the casing head, <br />the augers must be abandoned also. <br />When an obstruction is encountered that cannot be passed or an existing <br />utility is damaged, cutting of the pavement for inspection will be <br />approved by the local Maintenance Engineer or his representative, when <br />consideration of all pertinent facts indicate that such action would offer <br />09/03 16200 -16 03- 1438.A -R <br />�1 <br />