«OPTIMIZATION OF JUTE GEOTEXTILES IN PAVEMENT DESIGN STATE OF THE ART SHIVANI SRIDHAR & PAVITHRA L Civil Engineering Department Meenakshi Sundararajan ...»
Index Copernicus Value: 3.0 - Articles can be sent to email@example.com Optimization of Jute Geotextilesin Pavement Design Initial Traﬃc Initial traﬃc is determined in terms of commercial vehicles per day (CVPD). For the structural design of the pavement only commercial vehicles are considered assuming laden weight of three tonnes or more and their axle loading will be considered. Estimate of the initial daily average traﬃc ﬂow for any road should normally be based on 7-day 24hour classiﬁed traﬃc counts (ADT). In case of new roads, traﬃc estimates can be made on the basis of potential land use and traﬃc on existing routes in the area.
Traﬃc Growth Rate Traﬃc growth rates can be estimated (i) by studying the past trends of traﬃc growth, and (ii) by establishing econometric models. If adequate data is not available, it is recommended that an average annual growth rate of 7.5 percent may be adopted.
Design Life For the purpose of the pavement design, the design life is deﬁned in terms of the cumulative number of standard axles that can be carried before strengthening of the pavement is necessary. It is recommended that pavements for arterial roads like NH, SH should be designed for a life of 15 years, EH and urban roads for 20 years and other categories of roads for 10 to 15 years.
Vehicle Damage Factor
The vehicle damage factor (VDF) is a multiplier for converting the number of commercial vehicles of diﬀerent axle loads and axle conﬁgurations to the number of standard axle-load repetitions. It is deﬁned as equivalent number of standard axles per commercial vehicle. The VDF varies with the axle conﬁguration, axle loading, terrain, type of road, and from region to region. The axle load equivalency factors are used to convert diﬀerent axle load repetitions into equivalent standard axle load repetitions.
Vehicle Distribution A realistic assessment of distribution of commercial traﬃc by direction and by lane is necessary as it directly aﬀects the total equivalent standard axle load application used in the design. Until reliable data is available, the following distribution may be assumed.
Two-Lane Single Carriageway Roads The design should be based on 75 % of the commercial vehicles in both directions.
Pavement thickness design charts For the design of pavements to carry traﬃc in the range of 1 to 10 msa, use chart 1 and for traﬃc in the range 10 to 150 msa, use chart 2 of IRC:37 2001. The design curves relate pavement thickness to the cumulative number of standard axles to be carried over the design life for diﬀerent sub-grade CBR values ranging from 2 % to 10 %. The design charts will give the total thickness of the pavement for the above inputs. The total thickness consists of granular sub-base, granular base and bituminous surfacing.
TWO WAY LANE DESIGNA two-lane expressway is an expressway with only one lane in each direction, and usually no median barrier. It may be built that way because of constraints, or may be intended for expansion once traffic volumes rise. The term super two is often used by road geeks for this type of road, but traffic engineers use that term for a high-quality surface road.
Most of these roads are not tolled.
The empirical formula to calculation of msa Nṣ=365*A*[(1+r)^n -1]*Fr N = the cumulative number of standard axles to be catered for in the design in terms of msa A = Initial traffic in the year of completion of construction in terms of the no. of commercial vehicles per day.
Total pavement thickness for CBR 4% and traﬃc 7.2 msa from IRC:37 2001 chart1 = 660 mm
•Base course thickness=245mm
The design procedure given by IRC makes use of the CBR value, million standard axle concept, and vehicle damage factor. Traﬃc distribution along the lanes are taken into account. The design is meant for design traﬃc which is Index Copernicus Value: 3.0 - Articles can be sent to firstname.lastname@example.org Optimization of Jute Geotextilesin Pavement Design arrived at using a growth rate
So ANSYS, which enables to simulate tests or working conditions, enables to test in virtual environment before manufacturing prototypes of products. Furthermore, determining and improving weak points, computing life and foreseeing probable problems are possible by 3D simulations in virtual environment.
Road maintenance is one of the important component of the entire road system. Various types of failures in pavement ranging from minor and localized failures to major and general failures do take place on roads. The failures may occur one or combination of several causes.
General Causes of Failure In Pavement
• Defect in quality of material used.
• Defect in construction method and quality control during construction.
• Inadequate surface or subsurface drainage.
• Settlement of foundation.
• Environmental factors.
FAILURE DESIGN FOR FATIGUE
The increase in cost is compensated by increase in life cycle and low maintenance cost of the pavement
CONCLUSIONSHence a flexible pavement incorporated with JGT was designed and stress distribution was analysed using ANSYS. The failure criteria of the pavement was also designed. The cost comparison of normal pavement and JGT pavement was done. From the entire analysis it was found that rainwater collected by the roadside drained faster than usual in JGT roads. These roads will be stronger and last longer than normal roads. They will not develop holes after the monsoons. By using jute, a road's life can be increased by three to four years. When it does degenerate, it will become a part of the soil as it is biodegradable. Since no new technology or industrial infrastructure is required for the preparation of JGT, its availability is more. Production is also based on existing manufacturing process. It addresses soil related problems and strengthens roads. JGT deserves special encouragement from the decision-makers for its eco compatibility and competitive price.
1. IRC 37:2001- Indian road congress code for design of pavement
2. IS:2386Part 1V-1963- aggregate selection and test for aggregate in road work.
3. Highway engineering by S.K.Garg Index Copernicus Value: 3.0 - Articles can be sent to email@example.com Optimization of Jute Geotextilesin Pavement Design
4. C.E.G.Justo published by NEM CHAND BRO.
5. Highway engineering by S.C. Rangwala published by Charotar Publishing House Pvt.
6. Highway design and construction by A.G.Bruce.
7. Choudhury, P. K. Chatterjee, P. K. and Dutta, U. 1999 A Low Tech. Approach for Forests. 1 st Asia – Pasific Conference on Water & Bioengineering for erosion control & slope stabilization.
8. Juyal, G. P. and Dadhwal, K.S.. 1996. Geojute for erosion control with special reference to mine-spoil rehabilitation. Indian Journal of Soil Conservation, Vol.24 Impact Factor(JCC): 1.9586 - This article can be downloaded from www.impactjournals.us