1、Standard Practice for Determining Rut Depth in Pavements AASHTO Designation: R 48-10 (2013) American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS 5a R 48-1 AASHTO Standard Practice for Determining Rut Depth in Pavements
2、AASHTO Designation: R 48-10 (2013) 1. SCOPE 1.1. This practice describes a method for determining rut depth in pavement surfaces from transverse profile measurements. Five transverse profile points are the minimum number of points required to determine rut depth. While this practice is based on a fi
3、ve-measurement transverse profile, more than five measurements greatly improve the accuracy and enhance the likelihood of identifying the maximum and average rut depth given survey vehicle wander and various rut configurations. 1.2. Procedures are defined for measuring a transverse profile and deriv
4、ing a rut depth, but detailed specifications are not included for equipment, instruments, or software used to make the measurements. Any equipment and/or procedure that can measure as specified, with the accuracy stipulated herein, and that can be adequately calibrated is acceptable for this method.
5、 1.3. This practice does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this protocol to establish appropriate safety and health practices and determine the applicability of regulatory limitations related to and prior to it
6、s use. 2. REFERENCED DOCUMENT 2.1. FHWA Document: FHWA-RD-01-024, Characterization of Transverse Profiles, Federal Highway Administration, 2001 3. TERMINOLOGY 3.1. ruta longitudinal depression in a wheelpath consisting of consecutive rut depth determinations that measure a depression and extend for
7、more than 50 m (150 ft). 3.2. summary intervala longitudinal portion of a pavement lane over which the data are summarized as defined by the agency. This distance is generally 0.1 km (0.1 mile). 4. SIGNIFICANCE AND USE 4.1. This practice outlines standard procedures for measuring a transverse profil
8、e of the pavement from which a rut depth may be derived and summarizing the rut depth over a designated interval. Its purpose is to produce consistent estimations of rut depth for network-level pavement management. The intention is to measure rut depth in a vehicle traveling in the designated lane a
9、t highway speeds. 2014 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS 5a R 48-2 AASHTO 5. RUT MEASUREMENT 5.1. Each agency designates the lane(s) and direction(s) of travel to be surveyed based on sound e
10、ngineering principles and management needs within the agency. 5.2. Transverse profiles should be measured at a maximum spacing of 10 m (33 ft) in the longitudinal direction for the purpose of determining rut depth. 5.3. Transverse profiles are measured across both wheelpaths of the survey lane. The
11、goal of this practice is to obtain a transverse profile from which the depth of both ruts in a traffic lane can be derived. The reported summary statistics are the deepest rut found in each wheelpath and the average rut depth within the longitudinal summary interval. 5.3.1. The transverse locations
12、for the five-measurement procedure are shown in Figure 1. Figure 1Rut Depth Measurements 5.3.1.1. Spacing between measurement points depends on pavement geometry and typically is not even. 5.3.1.2. For best rut values, the span between D1and D5measurements should be no less than 500 mm (20 in.) smal
13、ler than the lane width. Depending on equipment, safe operation often dictates a shorter span, which compromises the rut value. 5.3.2. Each height measurement, Di, shall be made in a manner to minimize variability of measurement due to the pavement surface not being a true planar surface. 5.3.3. The
14、 depth measurements shall be made to a resolution of 3 mm (0.12 in.) and an accuracy of 3 mm (0.12 in.) with a 95 percent confidence. 5.3.4. The Basic Five-Point Rut Depth Calculations: 122oDMRD+= (1) 542iMDRD+= (2) where: 2014 by the American Association of State Highway and Transportation Official
15、s.All rights reserved. Duplication is a violation of applicable law.TS 5a R 48-3 AASHTO 152DDM+= or D3,whichever is less; (3) Ro= rut depth outside wheelpath estimate, mm; Ri= rut depth inside wheelpath estimate, mm; and D1, D2. D5= height measured as shown in Figure 1 (mm). Note 1This calculation a
16、llows for a negative rut depth. The negative rut can come from unusual cross sections, lateral offset of the measurement location, or atypical rut configurations. 5.3.5. The transverse profile is determined on the basis of the vertical distance between an imaginary string line run across the traffic
17、 lane from the shoulder to the lane line. The string line may bend at the hump between the wheelpaths where the hump is higher than the outside and inside edges of the lane. For manual measurements, the use of a string line will require D1and D5to be zero. Note 2This procedure is defined with knowle
18、dge of FHWA-RD-01-024 Characterization of Transverse Profiles, which compared ruts calculated from three- and five-point measurements to significantly denser systems. Users of this standard are advised to review this reference when making transverse measurement collection system decisions. 5.3.6. Th
19、e five-point system has limited accuracy due to variances in rut configuration and vehicle wander during the collection process. These limitations are further complicated by keeping the sensor systems within a safe envelope while traveling the road. Note 3The addition of two sensors at each primary
20、measurement location (D1, D2, D3, D4, D5) spaced 150 mm (6 in.) apart and the application of appropriate algorithms dramatically improve the reliability of the derived rut values. For maximum effectiveness, both of the outside sensors need to target beyond the 2300-mm (90-in.) dimension at each end
21、to extend the simulated string to within 250 mm (10 in.) of the lane width. 5.3.7. Technology is available to provide more than 1000 data points across the entire lane width. With such a transverse profile measurement, algorithms can be applied that remove texture effects, compensate for vehicle wan
22、der, and resolve a string-line rut value for each wheelpath. This is the preferred methodology for rut data collection. 6. OBTAINING THE DATA 6.1. Obtain and store the maximum and average rut depth determined from each wheelpath within the selected data summary interval. 7. REPORT 7.1. At a minimum,
23、 record the following data: 7.1.1. Section IdentificationRecord information that the agency has available to locate the section using its current referencing system; 7.1.2. Date of collection; 7.1.3. Length of data collection section, km (miles); 7.1.4. Maximum rut depth in each wheelpath for each s
24、ummary interval; 7.1.5. Average rut depth in each wheelpath for each summary interval; 7.1.6. Sampling interval, m (ft); 2014 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS 5a R 48-4 AASHTO 7.1.7. Summary
25、 interval, km (mi); and 7.1.8. Method agency utilizes to calculate maximum rut depth and average rut depth when negative rut depths are measured. 8. KEYWORDS 8.1. Pavement; pavement distortion; pavement distress; pavement evaluation; pavement management; pavement monitoring; rut; transverse profile;
26、 wheelpath; five-point rut estimate. 9. REFERENCES 9.1. AASHTO. Guide for Design of Pavement Structures. American Association of State Highway and Transportation Officials, Washington, DC, 1993. 9.2. ASTM Standard E 1703/E 1703M, 1995 (2005). “Standard Test Method for Measuring Rut-Depth of Pavement
27、 Surfaces Using a Straightedge.” ASTM International, West Conshohocken, PA. 9.3. SHRP. Distress Identification Manual for the Long-Term Pavement Performance Project. Strategic Highway Research Program, SHRP-P-338, Washington, DC, 1993. APPENDIX (Nonmandatory Information) X1. GUIDELINESQUALITY ASSURA
28、NCE PLAN X1.1. Quality Assurance PlanEach agency shall develop a quality assurance plan. The plan shall include survey personnel certification training records, accuracy of the equipment, daily quality control procedures, and periodic and ongoing quality control. The following guidelines can be used
29、 for developing such a plan. X1.2. Certification and TrainingAgencies are individually responsible for training and/or certifying their data collection personnel and contractors for proficiency in using the profile measuring equipment according to this practice and other applicable agency procedures
30、. X1.3. Equipment CalibrationEquipment calibration (accelerometers and noncontact sensors) is done in accordance with specific manufacturer recommendations. The equipment must operate within the manufacturers specifications. A regular maintenance and testing program is established for the equipment
31、in accordance with the manufacturers recommendations. X1.4. Verification SectionsVerification sections are selected with known rut depths. These sections are measured by equipment operators on a regular basis. Evaluations of these measurements can provide information about the accuracy of field meas
32、urements and give insight into needed equipment calibration. Verification sections are rotated on a regular basis in order to assure that the operators are not repeating previously known rut depth values during the verification. An alternate to verification sections is to remeasure and compare up to
33、 5 percent of the data as a daily or weekly quality check. 2014 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS 5a R 48-5 AASHTO X1.5. Quality ChecksAdditional quality checks can be made by comparing the m
34、ost recent rut depth statistics with current measurements. At locations where large changes occur, the pavement manager may require additional checks of the data. 2014 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.
