601.01 420 SECTION 601 – TIMBER STRUCTURES
601.01 Description ................................ ................................ ................... 420
601.02 Materials ................................ ................................ ...................... 420
601.03 Reserved ................................ ................................ ....................... 421
601.04 Prelimin ary Work ................................ ................................ ......... 421
601.05 Care and Protection of Timber ................................ ..................... 421
601.06 Components of Timber Structures ................................ ............... 421
601.07 Erection ................................ ................................ ........................ 424
601.08 Paint and Painting ................................ ................................ ........ 425
601.09 Final Cleanup ................................ ................................ ............... 426
601.10 Method of Measurement ................................ .............................. 426
601.11 Basis of Payment ................................ ................................ .......... 426
DESCRIPTION
601.01 Description
This work consists of constructing structures or parts of structures, other than piling, composed of timber, treated or untreated, or a combination of both, on prepared foundations at the locations shown on the Plans or as directed by the Engineer. Construct those parts of timber structures to be constructed with materials other than timber, such as concrete and steel, as specified in the Sections pertaining t o the respective types of structure. MATERIALS
601.02 Materials
Provide materials as specified in: Timber ................................ ................................ ......................... 911 Provide timber of the dimensions shown on the Plans. The dimensions on the Plans are intended to represent the co mmercial product. 601.03 421 Untreated timber used for mud sills shall be heart cedar, heart cypress, redwood, or other durable timber. Obtain the Engineer’s approval of the design of ring or shear plate timber connectors. Provide connectors of galvanized metal meet ing the appropriate ASTM standard. Provide hardware for timber structures of the design, size, kind, and composition shown on the Plans or as directed by the Engineer.
601.03 Reserved
CONSTRUCTION REQUIREMENTS
601.04 Preliminary Work
Perform Clearing and Grubbing, Removal of Structures and Obstructions, Excavation and Undercutting, Structure Excavation, Foundation Preparation and Backfill, and Embankment Construction as specified in 201, 202, 203, 204, and 205, respectively.
601.05 Care and Protection of Timber
Handle all timber with care, and store upon platforms, skids, or o ther supports at least 12 inches above the ground surface. Stack and strip timber to allow for the free circulation of air between the tiers and courses. Cover the stacked timber. Clear the ground underneath and in the vicinity of the timber of all weeds, rubbish, and other objectionable material, and shape to allow surface water flow to drain away from the stockpiled material.
601.06 Components of Timber Structures
A.Mud Sills Firmly and evenly bed mud sills to a solid bearing and tamp in place.
B.Concrete Pedestals Finish concrete pedestals for the support of framed bents so that the sills or posts will receive an even and uniform bearing. Slope the tops of pedestals pro jecting outside the bearing area downward to direct water away from the bearings. Set dowels, of not less than ¾ inches in 601.06 422 diameter and projecting the proper distance above the tops of the pedestals, 9 inches in the pedestal when they are being cast.
C.Sills Secure sills with ¾-inch diameter drift bolts extending into the mud sills, piles, or pedestals at least 9 inches. When possible, remove all earth from contact with sills to provide free circulation of air around the sills.
D.Caps Set caps as shown on the Plans, to have full and even bearing on piles or other supports in the bent, and to provide even bearing and full contact with the stringers placed on the caps. Secure caps to each pile or post by a ¾-inch drift bolt p laced approximately at the center of the pile or post and extending through the cap and at least 9 inches into the pile or post. Secure caps to other supports as shown on the Plans.
E.Posts for Bents Fasten posts to sills and pedestals with dowels of not less than ¾ inches in diameter extending into posts and sills as shown on the Plans.
F.Framing Cut and frame truss and bent timbers to a close fit in s uch manner that they will ha ve an even bearing over the entire contact surface of the joint. Do not perform any blocking or shimming when making joints. The Engineer will reject open joints . Ensure that mortises are true to size for their full depth, a nd tenons make a snug fit therein. Mortises and tenons shall be draw -bored.
G.Stringers Set and place all stringers to the required elevations to give flooring an even bearing at all contacts or intersections. Size stringers at bearings and place in position so that knots near edges will be in the top portion of the stringer. 601.06 423 Unless otherwise specified, outside stringers shall have butt joints, but frame interior stringers to bear ove r the full width of floor beam or cap at each end of the stringer. Separate the ends of untreated stringers at least ½ inch to allow for air circulation, and securely fasten the ends to the timber upon which they rest. Ensure that cross -bridging between st ringers is neatly and accurately framed and securely toe -nailed with at least two nails in each end.
H.Flooring Construct all flooring as shown on the Plans or as directed by the Engineer. Ensure that flooring has even, full, and uniform free bearing on each and all stringers, and is not pulled or warped to have such bearing. Only use shims and wedges with the Engineer’s approval. When constructing timber flooring, take care to place flooring pieces of the same th ickness adjacent to each other.
I.Wheel Guards Construct wheel guards on each side of the roadway as shown on the Plans. Place the wheel guards in sections not less than 12 feet in length, unless otherwise shown on the Plans or direct ed by the Engineer. Unless otherwise indicated, fasten wheel guards with 5/8-inch bolts not to exceed 5 -foot 3-inch cent ers. Fasten the ends of all wheel guards sections. The bolts shall extend entirely through the riser blocks and floor plank.
J.Railing Unless otherwise indicated or directed , provide railings of untreated, dressed lumber, constructed in a workmanlike and substantial manner . Construct the railings as shown on the Plans and to be reasonably true to line and grade. Paint the railings.
K.Bore Holes Bore holes as follows: 601.07 424 1. Round Bolts, Spikes, and Dowels. Use a bit 1/16 in ch less in diameter than the bolt, spike, or dowel to be used. The diameter of the holes for square bolts, spikes, or dowels shall be equal to the least dimension of the bolt or dowel.
2.Machine Bolts. Use a bit of the same diameter as the bolt.
3.Rods. Use a bit 1/16 in ch greater in diameter than the rod.
4.Screws. Use a bit slightly smaller than the body of the screw at the base of the thread, but not to the full depth of the screw. Re-treat all bolt holes bored after treatment with an approved treatm ent. Plug unfilled holes, after being treated, with treated plugs.
L.Bolts, Nuts, and Washers Provide b olts, nuts, and washers of the kinds and sizes specified. Bolts shall have square heads and nuts. All bolts shall be galvanized. Vertical bolts shall have the nuts on the lower end. Use a washer under the head or nut of all bolts or lag screws coming in contact with timber. Washers shall be of the same character as the bolt or screw with which they are used.
M.Countersinking Countersink nuts and bolt heads as directed by the Engineer. Fill the recesses formed by countersinking with hot tar pitch.
N.Spiking When using spikes to spike one member to another, with spikes 7 inches or longer as shown on the Plans, or when necessary in erection, drill holes through the member 1/16 inch less than the diameter of the spike that is to be driven. Drive spikes to the depth required to embed the full thickness of the head into the timber.
601.07 Erection
In erecting timber structures, or parts of structures, allow for the typical variations in Plans dimensions from commercial dimensi ons of timber to 601.08 425 obtain the required finished elevations and finished dimensions of the structure, without the use of shims or blocks. Position and fasten timbers as shown on the Plans or as directed by the Engineer. Perform all construction in a workmanli ke manner and ensure that the structure presents a neat finish and appearance when completed. Place planks with the heart side down, with ¼-inch openings between planks, unless otherwise shown on the Plans or directed by the Engineer. Fasten planks at eac h intersection to a nail strip or joist with two wire spikes of the size indicated or directed. In structures constructed in whole or in part of treated timber, thoroughly coat with an approved treatment all areas, where the timber surface is broken after treatment. Completely fill holes in treated timber caused by withdrawing bolts, nails, spikes, or other causes with an approved treatment. In structures constructed in whole or in part of untreated timber, thoroughly treat, as specified above, heads of pi les not encased in concrete, ends, tops, and all contact surfaces of truss members, laterals, and braces, before assembling. Thoroughly coat, as specified above, the back face of bulkheads and all other parts of timber in contact with earth. For timber sur faces that are to be painted in the completed structure, paint those portions coming in contact with other timber or material before being fastened or placed, as specified for railings in 601.08. Remove and replace, at no cost to the Department, all damaged or unsatisfactory timber.
601.08 Paint and Painting
Paint railings, except those or parts of those constructed of treated timber, with three coats of paint applied as specified in 603. Comply with the type, sequence, and colors shown on the Plans. Paint all metals, unless otherwise shown or directed, as specified in 603. 601.09 426 601.09 Final Cleanup When finishing a structure, clean exposed timber of any discoloration caused by the construction operations. Store all material becoming the property of the Department as directed by the Engineer. Perform final cleanup as specified in 104.10. COMPENSATION
601.10 Method of Measurement
The Department will measure Untreated Timber and Treated Timber, complete in place and accepted, by the 1,000 -board foot measure (MBFM) in accordance with 109. The Department will consider hardware used in a structure to be incidental to the Untreated Timber and Treated Timber bid items.
601.11 Basis of Payment
The Department will pay for accepted quantities of timber structures at the contract prices as follows: Item Pay Unit Treated Timber MBFM Untreated Timber MBFM 427 SECTION 602 – STEEL STRUCTURES
602.01 Description ................................ ................................ ................... 428
602.02 Materials ................................ ................................ ...................... 428
602.03 Reserv ed ................................ ................................ ....................... 429
602.04 Shop Inspection ................................ ................................ ............ 429
602.05 General ................................ ................................ ......................... 430
602.06 Bolt Holes ................................ ................................ .................... 435
602.07 Punched Holes ................................ ................................ ............. 436
602.08 Re amed or Drilled Holes ................................ .............................. 436
602.09 Preparation of Field Connections ................................ ................. 436
602.10 Accuracy of Punched and Drilled Holes ................................ ...... 437
602.11 Accuracy of Reamed and Drilled Holes ................................ ....... 437
602.12 Fitting for Bolting ................................ ................................ ........ 438
602.13 Shop Assembling ................................ ................................ ......... 438
602.14 Drifting of Holes ................................ ................................ .......... 440
602.15 Match -Marking ................................ ................................ ............ 440
602.16 Bolts and Bolted Connections ................................ ...................... 441
602.17 Connections Using High Strength Bolts ................................ ...... 442
602.18 Plate Cut Edges ................................ ................................ ............ 460
602.19 Welds ................................ ................................ ........................... 460
602.20 Facing of Bearing Surfaces ................................ .......................... 462
602.21 Abutting Joints ................................ ................................ ............. 462
602.22 End Connection Angles ................................ ............................... 462
602.23 Lacing Bars ................................ ................................ .................. 462
602.24 Fabrication of Members ................................ ............................... 463
602.25 Web Plates ................................ ................................ ................... 463
602.26 Bent P lates ................................ ................................ ................... 463
602.27 Fit of Stiffeners ................................ ................................ ............ 464
602.28 Eyebars ................................ ................................ ......................... 464
602.29 Annealing and Stress Relieving ................................ ................... 465
602.30 Pins and Rollers ................................ ................................ ........... 465
602.31 Boring Pin Holes ................................ ................................ .......... 466
602.32 Pin Clearances ................................ ................................ .............. 466
Referenced in this section
Sections that cite this one
TIMBER STRUCTURES in other states
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Source: Tennessee Standard Specifications for Road and Bridge Construction, 2021 Edition. Pages 429–435 of 1,072. View official source ↗