1、 CHAPTER 14 CULVERT INSPECTION, MATERIAL SELECTION, AND REHABILITATION GUIDELINE 2007 by the American Association of State Highway and Transportation Officials. 2007 by the American Association of State Highway and Transportation Officials.CHAPTER 14 TABLE OF CONTENTS 14.1 INTRODUCTION. 14-1 14.2 IN
2、SPECTION 14-2 14.2.1 Safety 14-2 14.2.1.1 OSHA Regulations 14-2 14.2.1.2 Special Considerations 14-2 14.2.2 Frequency of Inspection 14-3 14.2.3 Inspection Protocol . 14-4 14.2.3.1 Preliminary Information 14-4 14.2.3.2 Equipment Needed 14-5 14.2.3.3 Inspector Qualifications 14-5 14.2.4 Site Visit . 1
3、4-6 14.2.4.1 Roadway Surface and Side Slopes 14-6 14.2.4.2 Waterway 14-7 14.2.4.2.1 Culvert Inlet. 14-7 14.2.4.2.2 Culvert Outlet 14-7 14.2.4.2.3 Inside of Culvert 14-8 14.2.5 Special Investigation Procedures 14-10 14.2.5.1 Failure of a Culvert during Construction. 14-10 14.2.5.2 Failure of an Exist
4、ing Culvert . 14-12 14.2.5.3 Special Techniques 14-13 14.2.6 Inspection Report Form and Documentation 14-13 14.2.7 Distribution of Information. 14-13 14.3 FACTORS INFLUENCING SERVICE LIFE . 14-14 14.3.1 Corrosion 14-15 14.3.1.1 Hydrogen Ion Concentration (pH). 14-16 14.3.1.2 Soil Resistivity 14-16 1
5、4.3.1.3 Chlorides . 14-17 14.3.1.4 Sulfates 14-17 14.3.1.5 Industrial Effluents 14-17 14.3.1.6 Stray Electrical Current. 14-17 14.3.2 Abrasion 14-18 14.3.2.1 Debris 14-18 14.3.2.2 Bedload 14-19 14.3.3 Loss of Structural Integrity . 14-20 14.3.3.1 Joint Separation . 14-20 14.3.3.2 Misalignment. 14-21
6、 14.3.3.3 Deflection 14-21 14.3.3.4 Seam Defects. 14-22 14.3.3.5 Stream/Roadway Embankment Erosion 14-22 2007 by the American Association of State Highway and Transportation Officials.Highway Drainage Guidelines 14-iv 14.4 MATERIAL SELECTION AND ESTIMATING SERVICE LIFE .14-22 14.4.1 Culvert Material
7、s .14-23 14.4.1.1 Concrete Culverts.14-23 14.4.1.2 Corrugated Metal Pipe .14-24 14.4.1.2.1 Corrugated Steel Pipe.14-24 14.4.1.2.2 Corrugated Aluminum Pipe .14-25 14.4.1.3 Plastic Pipe.14-25 14.4.1.3.1 High-Density Polyethylene 14-26 14.4.1.3.2 Polyvinyl Chloride .14-26 14.4.1.4 Other 14-27 14.4.2 Pr
8、otective Coatings14-27 14.4.2.1 Zinc Galvanizing14-27 14.4.2.2 Aluminizing .14-27 14.4.2.3 Asphaltic Coatings.14-28 14.4.2.3.1 Bituminous .14-28 14.4.2.3.2 Fiber-Bonded Bituminous 14-29 14.4.2.3.3 Asphalt Mastic14-29 14.4.2.3.4 Polymerized Asphalt 14-29 14.4.2.4 Polymeric Sheet Coating14-29 14.4.2.5
9、 Concrete Coatings14-29 14.4.3 Alternative Materials .14-30 14.5 CULVERT REPAIR .14-30 14.5.1 Rehabilitation Methods .14-31 14.5.1.1 Grouting.14-31 14.5.1.2 Invert Paving and Plating.14-31 14.5.1.3 Sliplining14-32 14.5.1.4 Trenchless Relining .14-34 14.5.1.4.1 Cured-in-Place Pipe Lining14-35 14.5.1.
10、4.2 Fold and Form Lining 14-36 14.5.1.4.3 Polyvinyl Chloride (PVC) Pipe Lining System .14-37 14.5.1.4.4 Pipe Bursting14-37 14.5.1.4.5 Joint Sealing .14-38 14.5.1.5 Cement Mortar Lining .14-38 14.5.1.6 Epoxy Lining .14-38 14.5.2 Replacement Methods .14-38 14.5.2.1 Open Cut (Trench) Method14-39 14.5.2
11、.2 Trenchless Excavation Construction (TEC) Methods .14-39 14.5.2.2.1 Pipe Jacking .14-39 14.5.2.2.2 Horizontal Earth Boring (HEB) .14-41 14.5.2.2.3 Utility Tunnels (UT).14-42 14.6 REFERENCES 14-43 APPENDIX 14A .14-45 14A.1 Culvert Inspection Rating Form (Adapted from Reference (12)14-45 2007 by the
12、 American Association of State Highway and Transportation Officials.Culvert Inspection, Material Selection, and Rehabilitation Guideline 14-v14A.2 CalTrans Guide for the Protection of Reinforced and Unreinforced Concrete against Acid and Sulfate Exposure Conditions 14-46 14A.3 U.S. Bureau of Reclama
13、tion Criteria for Sulfate-Resisting Concrete Pipe. 14-46 14A.4 CalTrans Service Life Chart 14-47 14A.5 AISI Service Life Chart (22). 14-48 2007 by the American Association of State Highway and Transportation Officials.Chapter 14 Culvert Inspection, Material Selection, and Rehabilitation Guideline 14
14、.1 INTRODUCTION Drainage facilities, like all other elements of the highway system, deteriorate and decay due to the persistent forces of nature. Processes such as abrasion, corrosion, and erosion can lead to structural deficiencies and shorten the anticipated service life of drainage facilities, ev
15、entually necessitating some type of repair or replacement. The purpose of this chapter is to discuss the various processes that can lead to culvert failure and the factors to be considered in selecting an appropriate repair or rehabilitative strategy. Any determination of appropriateness must consid
16、er many of the factors that led to the original design conclusions, such as existing conditions, projections of future needs, material availability, cost, and environmental compatibility. In addition, the designer has the opportunity to evaluate what has or has not worked at the locations in questio
17、n and the ability to incorporate new technologies that may not have existed at the time of the original design. In addition, this chapter will present information to help designers select culvert materials that have the greatest potential to attain the necessary design service life, given a variety
18、of site conditions and constraints. Many thousands of kilometers miles of roadways were constructed during the building boom of the 1950s and 1960s as part of the development of our system of interstate highways. To protect the vast investment in this system and the network of other State and local
19、roads, pavement management systems and bridge management systems have been developed and adopted. Although bridge management systems include those culverts with a span in excess of 6.1 m (20 ft), few entities have adopted similar systematic programs for the inspection, evaluation, and repair of drai
20、nage structures with spans below the 6.1-m (20-ft) “bridge” designation. Perhaps because culverts are less visible than bridges and pavement, they have been given far less attention. However, the aging of the interstate system and other routes, combined with the lack of drainage system inspection an
21、d maintenance, has resulted in hundreds of thousands of culverts that are nearing the end of their useful service life. This chapter will address these non-bridge sized culverts. 2007 by the American Association of State Highway and Transportation Officials.Highway Drainage Guidelines 14-2 14.2 INSP
22、ECTION A key element of a successful culvert maintenance program is periodic inspection. A thorough inspection of all culverts on a regular basis will help identify any need for repair or rehabilitation. An established program will also allow the agency the flexibility to assign rehabilitation prior
23、ities, complete repair designs, and let construction contracts before a failure occurs. Before an inspection can begin, however, a plan must be developed to ensure that all necessary aspects are covered. This includes the procedures for a culvert inspection, the proper equipment to use, a form or ch
24、ecklist to follow for completeness and uniformity, a safety program, and requirements for inspector qualifications. This section will discuss these items in some detail and provide references for further information. See Reference (12) for a more thorough discussion of culvert inspection techniques.
25、 The FHWA document entitled Bridge Inspectors Training Manual also contains useful information on general inspection procedures and programs although, as the title indicates, its focus is on bridges instead of culverts. 14.2.1 Safety Culvert inspections must always be conducted with due consideratio
26、n to the safety of the inspectors and the public. Inspections should always be conducted in teams. The size of the team will be dependent on the number and type of tasks involved in the inspection. A two-person team will typically be sufficient for routine culvert inspections. However, traffic contr
27、ol operations must be considered where more complicated inspections will impede traffic, result in distractions to the motorists or subject inspectors to traffic hazards. 14.2.1.1 OSHA Regulations Occupational Safety and Health Authority (OSHA) regulations direct how certain activities must be perfo
28、rmed to ensure the safety of the worker. OSHA Standard 1910.146 concerns work within confined spaces, and this has been interpreted to include the interior of culverts. A confined space is defined to mean one that is large enough for an employee to enter and perform assigned work, yet has limited or
29、 restricted means of entry or exit and is not intended for continuous employee occupancy. Before entering a confined space, the air within the space must be tested in a prescribed manner with approved equipment to determine its safety for entry and work. Various States have gone on to more distinctl
30、y define a confined space. Before entering any culvert, the States applicable OSHA rules must be checked for compliance. This is not only a legal concern but, more importantly, it impacts the inspectors safety. 14.2.1.2 Special Considerations Though Federal and State regulations exist to ensure that
31、 safety is observed in all operations, many practical safety considerations exist as well. Inspecting a culvert may involve many hazardous conditions beyond the specifics of any safety law or regulation. As soon as an inspector steps out of a vehicle to begin an inspection, safety hazards are encoun
32、tered. In the vicinity of the roadway, these are traffic related. While on the roadway or shoulder area, traffic control signs, traffic delineators and even flaggers may be needed to alert the motorists and protect 2007 by the American Association of State Highway and Transportation Officials.Culver
33、t Inspection, Material Selection, and Rehabilitation Guideline 14-3the inspector. Most agencies will have their own traffic control procedures. These must not be neglected simply because one may only be on the roadway a few minutes. As one proceeds down the slope to look at the culvert itself, care
34、must be exercised. Roadway fill slopes may be steep or slippery, or they may contain hazards such as glass or debris thrown from vehicles. Ropes may even be needed if the slopes are especially steep or slippery. Not only could long falls occur, but the end of the fall could be into a deep pool at ei
35、ther the inlet or outlet of the culvert. Once down to the culvert, care must be taken not to fall into the stream. Even though the stream may appear shallow, deep scour holes may exist. While wading the stream, one must also be alert for the existence of scour holes. Probing poles should be used to
36、continually check the depth of the flow. Before entering a culvert, one should be aware of the weather in the immediate area and upstream. Flash floods can suddenly fill a culvert barrel while not raising water levels in the stream itself significantly. Rainfall on the upper reaches of a watershed m
37、ay arrive at the culvert site as runoff before any rain falls at the inspection site. Even entering the water with the proper equipment may be dangerous. Velocities could be too high to stand securely, streambed material may be slippery, or the water temperature might be too low to remain in the str
38、eam without the possibility of incurring hypothermia. Toxic chemicals may be in the water from upstream hazardous waste sites. Strong odors or unusual films or colors in the water may indicate potential hazards such as fire on the water or the presence of toxic fumes. Rats, snakes, and other animals
39、 use debris around or in the culvert as habitat. Poor lighting conditions may inhibit detection. The inspector should exercise caution when moving debris or silt to look more carefully at the culvert walls or invert. Air quality within a culvert barrel may not be safe for extended duration inspectio
40、ns. Any time a culvert is entered and the other end cannot be clearly seen, or if there is any concern regarding the air quality, the air should be tested. Testing must be performed with equipment specified by OSHA and State regulations, and the air must meet the regulatory standards (see Section 14
41、.2.1.1). In the interest of safety, culvert inspections should be made in teams of at least two people. When inspecting long culverts, a team of at least three is recommended. Two would be in the culvert, and the third member left outside, but within communicating distance of those inside. In the ev
42、ent of an accident, the third member should always go for help before attempting a rescue. 14.2.2 Frequency of Inspection Inspections may be made for several reasons. They may be regular and periodic as part of a routine. They may be special, because someone reported an unusual condition, or they mi
43、ght be spontaneous. The extent of the inspection may vary as well, often based on the need for the inspection. A complete culvert inspection should be conducted as a part of any preliminary engineering work to upgrade or rehabilitate the road surface. Identifying and including any culvert rehabilita
44、tion work in the road contract will usually prove economical and may avoid patching of new road surfaces due to later culvert repairs. 2007 by the American Association of State Highway and Transportation Officials.Highway Drainage Guidelines 14-4 Ideally, an inventory of all significant culverts is
45、maintained, and routine, complete inspections of every culvert in the system should be made every four years. Significant culverts are defined as those culverts in excess of 1200 mm (48 in.) in diameter. Culverts having noted non-serious deficiencies should be reinspected two years later to note any
46、 changes. If none are noted at that later inspection, it can be put back on the four-year schedule. If, on the other hand, the deficiencies have worsened, then a special schedule of inspection or even a rehabilitation plan will have to be established. If a non-solicited report of a deficiency is mad
47、e, a preliminary assessment should be made as soon as possible after receiving the report. Depending on the results of that assessment, further inspections or work may have to be scheduled. Spontaneous inspections may be made at any time. Usually, these will be for demonstration or training purposes
48、. They may also be made to try out new equipment or techniques. These inspections should never be substituted for a regularly scheduled inspection. There may be times when it is desirable to conduct on-site monitoring during a flood event. Such monitoring may be desirable to observe the actual direc
49、tion of flow during a highwater event, amount and type of debris, outlet velocities, and scour. In no case should the desire to perform the inspection take precedence over the safety of personnel. A post-flood inspection may be warranted if problems are observed or suspected. 14.2.3 Inspection Protocol Although a routine inspection sequence is not as important as a checklist for ensuring that all items are completed, a sequence can be helpful for several reasons. A logical sequence
