AASHTO HB-17 DIVISION II SEC 2-2002 Division II Construction - Removal of Existing Structures《现有结构的移除》.pdf

1、Section 2 REMOVAL OF EXISTING STRUCTURES 2.1 DESCRIPTION This work shall consist of the removal, wholly or in part, and satisfactory disposal, or salvage, of all bridges, retaining walls and other major structures which are des- ignated on the plans or in the special provisions to be re- moved. The

2、work also includes, unless otherwise speci- fied, any necessary excavation and the backfilling of trenches, holes or pits that result from such removal. 2.2 WORKING DRAWINGS Working drawings showing methods and sequence of removal shall be prepared: (1) when structures or portions of structure are s

3、pecified to be removed and salvaged, (2) when removal operations will be performed over or adja- cent to public traffic or railroad property, or (3) when called for by the plans or special provisions. At least 10 days prior to the proposed start of removal operations, the working drawings shall be s

4、ubmitted to the Engineer for approval. Removal work shall not begin until the draw- ings have been approved. Such approval shall not relieve the Contractor of any responsibility under the contract for the successful completion of the work. When salvage is required, the drawings shall clearly indicat

5、e the markings proposed to designate individual segments of the structure. 2.3 CONSTRUCTION 2.3.1 General Except for utilities and other items that the Engineer may direct the Contractor to leave intact, the Contractor shall raze, remove and dispose of each structure, or por- tion of structure, desi

6、gnated to be removed. All concrete and other foundations shall be removed to a depth of at least 2 feet below ground elevation or 3 feet below sub- grade elevation, whichever is lower. Unless otherwise specified, the Contractor has the option to either pull piles or cut them off at a point not less

7、than 2 feet below ground line. Cavities left from structure removal shall be back- filled to the level of the surrounding ground and, if within the area of roadway construction, shall be compacted to meet the requirements of the contract for embankment. Explosives shall not be used except at locatio

8、ns and under conditions cited by the project specifications. All blasting shall be completed before the placement of new work. 2.3.2 Salvage Materials which are designated to be salvaged under the contract, for reuse in the project or for future use by the Department, shall remain the property of th

9、e Depart- ment and shall be carefully removed in transportable sec- tions and stockpiled near the site at a location designated by the Engineer. The Contractor shall restore or replace damaged or destroyed material without additional com- pensation. Rivets and bolts that must be removed from steel s

10、truc- tures to be salvaged shall be removed by cutting the heads with a chisel, then punched or drilled from the hole, or by a method that will not injure the members for reuse and will meet the approval of the Engineer. All members or sections of steel structures shall be match-marked with paint in

11、 accordance with the diagram or plan approved by the Engineer prior to dismantling. All bolts and nails shall be removed from lumber deemed salvageable by the Engineer as part of the salvage of timber structures. 2.3.3 Partial Removal of Structures When structures are to be widened or modified and o

12、nly portions of the existing structure are to be removed, these portions shall be removed in such a manner as to leave the remaining structure undamaged and in proper condition for the use contemplated. Methods involving the use of blasting or wrecking balls shall not be used within any span or pier

13、 unless the entire span or pier is to be removed. Any damage to the portions remaining in ser- vice shall be repaired by the Contractor at his or her ex- pense. 48 1 482 HIGHWAY BRIDGES 2.3.3 Before beginning concrete removal operations involv- ing the removal of a portion of a monolithic concrete e

14、lement, a saw cut approximately 1-inch deep shall be made to a true line along the limits of removal on all faces of the element which will be visible in the completed work. Old concrete shall be carefully removed to the lines designated by drilling, chipping, or other methods ap- proved by the Engi

15、neer. The surfaces presented as a re- sult of this removal shall be reasonably true and even, with sharp straight corners that will permit a neat and workmanlike joint with the new construction or be satis- factory for the purpose intended. Where existing rein- forcing bars are to extend from the ex

16、isting structure into new construction, the concrete shall be removed so as to leave the projecting bars clean and undamaged. Where projecting bars are not to extend into the new construc- tion, they shall be cut off flush with the surface of the old concrete. During full depth removal of deck concr

17、ete over steel beams or girders which are to remain in place, the Con- tractor shall exercise care so as not to notch, gouge, or dis- tort the top flanges with jackhammers or other tools. Any damage shall be repaired at the Contractors expense. Re- pairs will be done as directed by the Engineer and

18、may in- clude grinding, welding, heat straightening, or member replacement, depending on the location and severity of the damage. 2.3.4 Disposal Any material not designated for salvage will belong to the Contractor. Except as provided herein, the Contractor shall store or dispose of such material ou

19、tside of the right of way. If the material is disposed of on private property, the Contractor shall secure written permission from the property owner and shall furnish a copy of each agree- ment to the Engineer. Waste materials may be disposed of in Department-owned sites when such sites are describ

20、ed in the special provisions. Unless otherwise provided in the special provisions, removed concrete may be buried in adjacent embank- ments, provided it is broken into pieces which can be readily handled and incorporated into embankments and is placed at a depth of not less than 3 feet below finishe

21、d grade and slope lines. The removed concrete shall not be buried in areas where piling is to be placed or within 10 feet of trees, pipelines, poles, buildings, or other perma- nent objects or stuctures, unless permitted by the Engi- neer. Removed concrete may also be disposed of outside the right-o

22、f-way as provided above. 2.4 MEASUREMENT AND PAYMENT The work as prescribed for by this item shall be mea- sured as each individual structure, or portion of a struc- ture, to be removed. Payment will be made on the basis of the lump sum bid price for the removal of each structure, or portion of stru

23、cture, as specified. The above prices and payments shall be full compen- sation for all work, labor, tools, equipment, excavation, backfilling, materials, and incidentals necessary to com- plete the work, including salvaging materials not to be reused in the project when such salvaging is specified

24、and not otherwise paid for. Full compensation for removing and salvaging materi- als that are to be reused in the project shall be considered as included in the contract prices paid for reconstructing, relocating or resetting the items involved, or in such other contract pay items that may be designated in the contract, and no additional compensation will be allowed therefore.