Mississippi Excavation and Grading

Key Concepts

Notice before excavation - Standard (non-submerged, non-emergency) excavation: the excavator must give not less than three (3) and not more than ten (10) working days' advance notice to Mississippi 811, Inc. (§ 77-13-5(1)(a)). - Submerged excavation: not less than seven (7) working days' advance written, electronic, or telephonic notice (§ 77-13-5(8)(a)). - Pre-marking is required before giving notice: mark the approximate boundary of the proposed excavation area with white paint, flags, stakes, or electronic pre-marking (§ 77-13-5(1)(b)). A single stake or single-point indicator represents that the area does not exceed fifty (50) feet in any direction from the pre-mark (§ 77-13-5(1)(b)). - The proposed excavation location is limited to an area reasonably believed completable within 20 calendar days and may not include any area where the excavator has already completed the excavation work (§ 77-13-5(1)(a)).

Ticket and mark validity / renewal - Standard: markings and the locate request ticket are valid 20 calendar days from the date and time the ticket is processed (§ 77-13-5(2)). - Submerged: thirty (30) calendar days (§ 77-13-5(8)(b)). - Renewal for standard excavation: at least three (3) and not more than four (4) working days before the expiration date (§ 77-13-5(3)).

Operator duties - Standard locate request: mark and report through PRIS within three (3) working days from ticket processing; if location is possible only by excavation, a reasonable additional period not to exceed four (4) working days total (§ 77-13-9(2)(a)). - Emergency excavation: operator must respond within two (2) hours of ticket processing (§ 77-13-9(2)(c)). - Design information request: respond within seven (7) working days by marking the approximate location, providing the best available description, or allowing the requester or other authorized person to inspect or copy drawings/records (§ 77-13-9(7)). - Facilities installed on or after January 1, 2010 must be installable so they can be located by a generally accepted electronic locating method (§ 77-13-9(5)). - Operators with underground utility lines, underground facilities, or submerged facilities in Mississippi must be members of Mississippi 811, Inc. (§ 77-13-17(2)).

Topic: Excavating and Grading

Key Concepts

Mississippi 811 notification - An excavator must give not less than three (3) and not more than ten (10) working days' advance notice to Mississippi 811, Inc. before beginning excavation (excluding emergencies and submerged excavation) — Miss. Code §77-13-5(1)(a). - "Approximate location of underground utility lines or facilities" must be accurate within eighteen (18) inches of the outside edge of the facility; for submerged facilities, fifteen (15) feet — §77-13-3(b). - "Excavate" excludes tilling for agricultural purposes less than 24 inches deep, and displacement less than 12 inches deep on private property by the owner without mechanical excavating equipment — §77-13-3(i). - A Design Information Request is for bidding/preconstruction planning and may not be used for excavation purposes — §77-13-3(g).

Excavation classifications (Section 203.01) - Unclassified — all material of whatever character except classes with separate pay items (203.01.1). - Rock — material that cannot be excavated without blasting, plus boulders/detached stones of one-half cubic yard or more (203.01.2). - Muck — saturated soil with organic content of at least six percent (6%) per MT-29 or AASHTO T 267 (203.01.3). - Excess — cannot be satisfactorily used or disposed of within the right-of-way (203.01.6). - Surplus — in excess or unsuitable for embankments but can be satisfactorily used or disposed of within the right-of-way (203.01.7). - Measurement: by cubic yard FM or LVM (203.04.1); site grading by acre or square yard (203.04.5). Removal of Obstructions is 202-A lump sum; specific items under 202-B per each, linear foot, square yard, or cubic yard (202.05).

Embankment and compaction (Section 203.03.8) - Embankment height to subgrade three feet or less: remove sod, vegetation and unsuitable soil, mix by plowing/scarifying/disk-harrowing to a depth of at least six inches, then compact to design soil density — 203.03.8.2(c). - Non-compacted layer thickness shall not exceed eight inches (203.03.8.3); structure backfill also in layers not exceeding eight inches loose (203.03.8.6). - Required density: basement soils 95.0 percent, design soils 98.0 percent. A test within minus two percent triggers a verification test, and the average of the two tests is the lot value (203.03.8.7). - Haul: within each balanced section, average haul is computed along the control line as the distance between the center of volume of the excavation in its original position and the center of volume of the corresponding embankment in its final position (205.04).

Key Concepts

Cave-in protection - Protection is required for every employee in an excavation except where the excavation is made entirely in stable rock, or is less than 5 feet deep and a competent person examines the ground and finds no indication of potential cave-in — §1926.652(a)(1). - Option 1 sloping: maximum allowable slope is 1½ horizontal to 1 vertical (34° from horizontal), corresponding to Type C — §1926.652(b)(1)(i); Appendix B to Subpart P, Table B-1. - Manufacturer's tabulated data: deviation from the manufacturer's specifications, recommendations and limitations is allowed only after the manufacturer issues specific written approval of that deviation — §1926.652(c)(2)(ii). - Support system removal: begins at and progresses from the bottom of the excavation, and backfilling progresses together with removal — §1926.652(e)(1)(v)-(vi). Before temporary removal of individual members, install other structural members to carry the loads — §1926.652(e)(1)(iv). - Shields: employees may not be in a shield while it is being installed, removed, or moved vertically — §1926.652(g)(1)(iv). - Employees may not work on faces of sloped or benched excavations above other employees unless those at lower levels are adequately protected from falling, rolling, or sliding material or equipment — §1926.652(f).

Competent person and inspections - Competent person = capable of identifying existing and predictable hazards and authorized to take prompt corrective measures — §1926.32(f). - Daily inspections by a competent person for evidence of possible cave-ins, failure of protective systems, hazardous atmospheres, or other hazardous conditions; before the shift and as needed, and after every rainstorm or hazard-increasing occurrence — §1926.651(k)(1). - Accident prevention programs must provide frequent and regular inspections of job sites, materials and equipment by competent persons designated by the employer — §1926.20(b)(2).