Structural Analysis of Two-Layer Pavement Systems
This study delves into the vertical interface deflection criteria for two-layer pavement systems in highway and transportation engineering. By analyzing the deflection factor and various parameters such as the modulus ratio and thickness-radius ratio, the design criteria for two-layer systems are explored. Steps to solve the vertical interface deflection are also outlined in detail.
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Pavement Structural Analysis Two-Layer Systems (Vertical interface deflection) Highway and Transportation Engineering Al-Mustansiriyah University 2020-2021 Dr. Rana Amir Yousif Dr. Abeer K. Jameel Yoder; E. J. and M. W. Witczak, Principles of Pavement Design , A Wiley- Interscience Publication, John Wiley & Sons Inc., U.S.A., 1975.
References Nicholas J. Garber and Lester A. Hoel. Traffic and Highway Engineering , Fourth Edition. Yoder; E. J. and M. W. Witczak, Principles of Pavement Design , A Wiley- Interscience Publication, John Wiley & Sons Inc., U.S.A., 1975. Yaug H. Huang, Pavement Analysis and Design , Prentic Hall Inc., U.S.A., 1993. AASHTO Guide for Design of Pavement Structures 1993 , AASHTO, American Association of State Highway and Transportation Officials, U.S.A., 1993. Oglesby Clarkson H., HighwayEngineering , John Wiley & Sons Inc., U.S.A., 1975. Yoder; E. J. and M. W. Witczak, Principles of Pavement Design , A Wiley- Interscience Publication, John Wiley & Sons Inc., U.S.A., 1975.
Two-Layer Systems Vertical Interface Deflection: The vertical interface deflection has also been used as a design criterion. Figure 2.19 can be used to determine the vertical interface deflection in a two-layer system (Huang, 1969c) . The deflection is expressed in terms of the deflection factor F by: (2.16) Yoder; E. J. and M. W. Witczak, Principles of Pavement Design , A Wiley- Interscience Publication, John Wiley & Sons Inc., U.S.A., 1975.
Two-Layer Systems ( (Vertical Interface Deflection) Yoder; E. J. and M. W. Witczak, Principles of Pavement Design , A Wiley- Interscience Publication, John Wiley & Sons Inc., U.S.A., 1975.
Two-Layer Systems ( (Vertical Interface Deflection) The deflection factor is a function of: 1.The modulus ratio El/E2. 2. Thickness radius ratio h1/a. 3. r/a. Where : r:is the radial distance from the center of loaded area. Yoder; E. J. and M. W. Witczak, Principles of Pavement Design , A Wiley- Interscience Publication, John Wiley & Sons Inc., U.S.A., 1975.
Two-Layer Systems ( (Vertical Interface Deflection) Steps to Solve Two-Layer Systems (Vertical Interface Deflection): Step 1 Find value. Find value. Find value. Yoder; E. J. and M. W. Witczak, Principles of Pavement Design , A Wiley- Interscience Publication, John Wiley & Sons Inc., U.S.A., 1975.
Two-Layer Systems ( (Vertical Interface Deflection) Steps to Solve Two-Layer Systems: Step 2 As example (if = 4 , = 1 and = 1.5 ) from Figure 2.19 please follow the chart Then F= 0.3 can obtain. 1 Yoder; E. J. and M. W. Witczak, Principles of Pavement Design , A Wiley- Interscience Publication, John Wiley & Sons Inc., U.S.A., 1975. 2
Two-Layer Systems ( (Vertical Interface Deflection) Example: Figure 2.20 shows a set of dual tires, each having contact radius 4.52 in . (115 mm) and contact pressure 70 psi (483 kPa) . The center-to- center spacing of the dual is 13 .5 in . (343 mm) . Layer 1 has thickness 6 in . (152 mm) and elastic modulus 100,000 psi (690 MPa) ; layer 2 has elastic modulus 10,000 psi (69 MPa) . Determine the vertical deflection at point A, which is on the interface beneath the center of one loaded area .? Yoder; E. J. and M. W. Witczak, Principles of Pavement Design , A Wiley- Interscience Publication, John Wiley & Sons Inc., U.S.A., 1975.
Two-Layer Systems ( (Vertical Interface Deflection) Solution: Given = 100,000/10,000 = 10 = 6 / 4.542 = 1.33 The deflection factor at point A due to the left load where : = 0 from Figure 2.19 F = 0.56 Yoder; E. J. and M. W. Witczak, Principles of Pavement Design , A Wiley- Interscience Publication, John Wiley & Sons Inc., U.S.A., 1975. E1/E2
Two-Layer Systems ( (Vertical Interface Deflection) Solution: The deflection factor at point A due to the right load where : = 13.5 / 4.52 = 2.99 from Figure 2.19 F = 0.28 By superposition F = 0.56 + 0.28 = 0.84 From Eq. 2.16 w = 70 * 4 .52/10,000 * 0.84 = 0.027 in . (0.69 mm) Yoder; E. J. and M. W. Witczak, Principles of Pavement Design , A Wiley- Interscience Publication, John Wiley & Sons Inc., U.S.A., 1975. E1/E2
Two-Layer Systems Dr. Rana Amir Yousif & Dr. Abeer K. Jameel Yoder; E. J. and M. W. Witczak, Principles of Pavement Design , A Wiley- Interscience Publication, John Wiley & Sons Inc., U.S.A., 1975.
