Hs 20 loading pavement design pdf

Hl93 aashto vehicular live loading truck tandem design. Loads are based on dual wheels, so actual wheel loads are 14 of axle load except for the front axle which is 12 of axle load. Aashto pavement thickness design guide when designing pavement thickness for flexible and rigid pavements, the following considerations should be used. Structural design of roads for fire trucks last updated december 23, 20. Aashto hl93 loading hs2044, design truck, design tandem. H20 vs h25 loading for hdpe pipe codes and standards.

In other words, there must be some assurance that a pavement will perform as intended given. Structural pavement design guidelines city of toronto december 14, 2006. Hl93 design tandem consist of twin axles spaced 4 1. Designers use h20 or hs20 from aashto, or specific axle configurations, to express the extreme load effect created by heavy vehicles such as transports, buses and fire trucks. Aashtos h20 and hs20 are live load ratings applied to the design of bridges or other suspended items e. Minimum cover heights in trafficked conditions pipe with diameters of 4 to 48inch installed subjected to aashto hl93, h25 or hs25 traffic loads must have. Designers use h 20 or hs 20 from aashto, or specific axle configurations, to express the extreme load effect created by heavy vehicles such as transports, buses and fire trucks. The third tire design parameter is that of tire size. Vehicular loads are typically based on the aashto h25 or hs25 configuration, figure 22, which represents a 25 ton 222 kn semitruck. Hl8 hs granular b granular a hl1 hl8 granular b granular a s1sp ara012712 pavement design methodologies.

Vegetated pavement surfaces are suitable for occasional use traffic with an engineered infill and base as shown in table 2. Quality asphalt pavement may be constructed in a wide range of soil, weather, and loading conditions. Hs25 three axles 5 tons20 tons20 ton wheel loads are one half of the axle loads re. Aashto loading of either h 20 or hs 20 is based on an axle load of 32 kips. The hs 20, 32,000 pound and the alternate truck 25,000 pound design axle are carried on dual wheels figure 1. American association of state highway transportation officials aashto published its bridge design criteria, commonly known as h20 or hs20. The reliability of the pavement design performance process is the probability that a pavement section designed using the process will perform satisfactorily over the traffic and environmental conditions for the design period aashto, 1993 1. The tire contact area for hs 2044 shall be assumed as a rectangle with a length in the direction of traffic of 10 inches, and. H25 loading codes and standards general discussion. H 20 loading specifications summary of top deck stresses under h 20 loading conditions 32,000 lbs14,500 kg the silva cell can support vehicle loading up to aashto h 20 rating of 32,000 lbs. If loadings other than those designated axe desired, they shall be obtained proportionately changing the weights shown for both the standard tnck and the corre sponding lane loads.

Manhole frame and cover load bearing definitions npca. Pavement design manual section 1 introduction page 1 1 introduction 1. Single axle loadings of 32 kips 145 kn, tandem axle loadings of 48 kip 220 kn. The hl93 designation consists of a design truck plus design lane load or design tandem plus design lane load, whichever produces the worst case. Aashtos h 20 and hs 20 are live load ratings applied to the design of bridges or other suspended items e. The 20year esal loading on this segment is the difference between the two numbers, or 9,580,000 esals. Here the notation m r is used only for roadbed resilient modulus while other notations such as e bs and e sb are used for modulus of base and subbase respectively 40. This design parameter is defined by the tires overall diameter, its section width, and the wheel rim diameter, figure 17 4. Depending on analysis technique and pavement type, you can. For example, increasing a rigid pavement from 9 to 10 inches in depth will approximately double the traffic loadings that can be accommodated by the pavement. It has 3 basic live loads for bridges called hl93 loading where h stands for highway and l stands for loading, developed in 1993. It specifies truck axle loading of 32,000 pounds or wheel loading of 16,000 pounds. Aggregate pavement surfaces are suitable for all types of traffic and frequencies up to aashto h hs 20 loading. A project traffic report is routinely developed as part of.

Any concrete pavement, built of any thickness, will have problems on a poorly designed and constructed subgrade or subbase. Calculate the average pressure intensity of the wheel loads on the soil plane on the outside top. At the time of this printing, the thruway authority has designed structures predominantly using. Design guide for detailed information for analyzing the intended design conditions. The average pressure intensity caused by a wheel load is calculated by equation 3.

The h15 bridge is based on a hypothetical vehicle with one 6,000 pound axle and one2 24,000 pound axle. H25 loading hs 25 loading rainstore3 has been independently. The 20 year esal loading on this segment is the difference between the two numbers, or 9,580,000 esals. H 20 and hs20 loading 8000 lbs 32,000 lbs h 20 loading 8000 lbs 32,000 lbs hs20 loading. The aashto design loads commonly used in the past were the hs 20 with a 32,000 pound axle load in the normal truck configuration, and a 24,000 pound axle load in the alternate load configuration figure 2. This loading is based on a hypothetical vehicle with one 8,000 pound axle and two 32,000 pound axles.

In bridge design we normally use hs20 loading, and if we were asked to use hs 25 loading we would have a corresponding increase in the fatigue distress. A 20 year design year 2009 shows cumulative esals of 10,074,000. You may need to increase your fatigue values by 25% in this case. Aashto guide for the design ofpavement structures resilient modulus is the primary material property that is used to characterize the roadbed soil and other structural layers for flexible pavement design in the 1993 aashto guide for the design of pavement structures. Conversely, the closer the axles in a group are, the greater the weight they may carry without increasing pavement deterioration beyond that occasioned by a single axle, dependent on the number of axles in the group. Proper design and construction are absolutely necessary if the pavement is to perform.

This guide presents examples of designs, procedures, and applications that have. Aashtos h 20 and hs20 are live load ratings applied to the design of bridges or other suspended items e. For highway loads, the minimum cover shall be measured from the top of the pipe to the bottom of flexible pavement or the top of the rigid pavement. It consists of truck axle loading of 32,000 lbs, or wheel loading of 16,000 lbs. H20 loading specifications summary of top deck stresses under h20 loading conditions 32,000 lbs14,500 kg the silva cell can support vehicle loading up to aashto h20 rating of 32,000 lbs. Concrete pavement design geometrics thicknesses joints materials most often influence cost. Guidelines for the design of buried steel pipe july 2001 i acknowledgments the following people with their affiliations contributed to this report. This is due to the extremely high axle weights that they exert. Structural design of roads for fire trucks last updated december 23, 20 a common question posed by design professionals is the ability of pavers to withstand fire truck loading.

Aggregate pavement surfaces are suitable for all types of traffic and frequencies up to aashto hhs20 loading. Guidelines for the design of buried steel pipe july 2001. The h loading consists of twoaxial truck the number following the h designation is the gross weight in tons of the standard truck h 2044 8 kips 32 kips h 1544 6 kips 24 kips 0. January 2005 implementation memo flexible pavement design manual. Grasspave2, gravelpave2, and slopetame2 can withstand 15,940 psi with. Figure 1 the geoblock5150 porous pavement system components design considerations function of the geoblock system components function of the grass paver structure the geoblock5150 units have three key purposes. Basc, bridge approach slab for concrete pavements this revision requires a 1inch thick bondbreaker when the approach slab is constructed on cementtreated base or cementstabilized backfill as recommended by the txdot pavement design manual. Vehicular loads are typically based on the aashto h25 or hs 25 configuration, figure 22, which represents a 25 ton 222 kn semitruck. Designers use h 20 or hs20 from aashto, or specific axle configurations, to express the extreme load effect created by heavy vehicles such as transports, buses and fire trucks. When h 2044 and hs 2044 loads are used for timber deck floor design, a modified form of standard loading is permitted by aashto. Principles of design load stresses volume change stresses curlingwarping stresses jointing or reinforcing.

It is commonly called as hs 20 44 where h stands for highway, s for semitrailer, 20 ton weight of the tractor 1st two axles and was proposed in 1994 2. Hs 25 three axles 5 tons 20 tons 20 ton wheel loads are one half of the axle loads re. It is commonly called as hs20 44 where h stands for highway, s for semitrailer, 20 ton weight of the tractor 1st two axles and was proposed in 1994 2. To obtain maximum negative moments, a pair of tandems should be considered, spaced at 8. Equivalent single axle load although it is not too difficult to determine a wheel or an axle load for an individual vehicle, it becomes quite complicated to determine the number and types of wheelaxle loads that a particular pavement will be subject to over its design life. Proper pavement design relative to loading is a significant factor in pavement life, and varies by highway system and the number of trucks in the traffic stream. Paul guyer is a registered civil engineer, mechanical engineer, fire protection engineer, and architect with over 35 years experience in the design of buildings and related. H20 loading, also known as hs20 loading, is the bridge design criteria established by the american association of state highway transportation officials, states the national precast concrete association foundation. This rating refers to the ability of a roadway to safely accommodate 34 axle vehicles, such as a large semitruck and trailer.

Such loadings could result in damage to the pavements andor the pipes. Date 2019 rigid pavement design manual rpdm 110118 2018 rigid pavement design manual rpdm. It is commonly called as hs20 44 where h stands for highway, s for semitrailer, 20 ton weight of the tractor 1st two axles and was proposed in. Instead of the 32,000pound axle load specified for the standard trucks, oneaxle loads of 24,000 pounds or twoaxle loads of 16,000 pounds each, spaced 4 feet apart, may be used aashto 3 figures 3. Highway loading is hl93 loading per aashto lrfd bridge design specifications. Aug 17, 2016 hl93 design tandem consist of twin axles spaced 4 1. The design tandem is the same as shown in figure 3 except that the axle load is 25,000 pounds. H25 loading hs25 loading rainstore3 has been independently.

This design criteria did not specifically address loading on construction castings, but due to casting. Poor subgradesubbase preparation can not be overcome with thickness. Since you are looking at a pavemet, not a structure. Minimum and maximum burial depths for corrugated hdpe. H 20 loading, also known as hs 20 loading, is the bridge design criteria established by the american association of state highway transportation officials, states the national precast concrete association foundation. There are font standard classes of highway loading. A design truck is identical to the hs20 load configurations shown in figure 2. When h 20 44 and hs 20 44 loads are used for timber deck floor design, a modified form of standard loading is permitted by aashto. Aashto loading of either h20 or hs20 is based on an axle load of 32 kips. However, reorganizational changes have resulted in a decision to issue this guidance as a standalone document under. Aug 30, 2016 this 2016 asphalt pavement design guide has been prepared to assist readers in understanding asphalt mix pavement design, construction, and rehabilitation. A 20year design year 2009 shows cumulative esals of 10,074,000. Rdgn042 pavement design for carriageway construction page 2 of 42 6.

However, reorganizational changes have resulted in a decision to issue this guidance as a standalone document under the title of adot pavement design manual. The aashto lrfd design loads are the hs 20 with a 32,000. Previously, guidance for pavement design activities was included in the materials preliminary engineering and design manual. The tire contact area for hs 20 44 shall be assumed as a rectangle with a length in the direction of traffic of 10 inches, and. Similarly in railroad applications, the standard load is.