Teodoru 2009) have developed a two-parameter formulation of beams-on-elastic-foundations involving the subgrade modulus and another parameter which considers the shear distortion of the soil and an assumption of the curved deformation pattern. However the above mentioned equations have limitations. As more and more engineers will use software to design foundations, it is essential for engineers to have a fundamental understanding of this soil parameter. Normally, shear failure governs for smaller foundations and settlement failure governs bigger foundations. Terzaghi in 1955 presented empirical relationships for determining the coefficient of subgrade reactions (ksf) for full-scale foundations, based on results from plate load tests. Then the corrected modulus of rupture is given by: Where p and ps are the pressures for unsoaked and soaked specimen as shown in Figure-3. Here, k = modulus or coefficient of subgrade reaction; p = applied pressure and s = deformation of soil settlement. 1 0 obj
A point at the center of the footing will experience the highest displacement. It is also important to note that the software default Ks value (10858 kN/m2/m) was exactly the same as the constant ratio calculated in Table 1. 2009, Beams on Elastic Foundation The Simplified Continuum Approach. SPRING CONSTANT AND SOIL. Several equations have been developed to estimate k s for elastic soils based on tests and theoretical analyses of which the methods for determination of k s value based on Vesic's [ 2 ] relation gave . For the first case, a constant subgrade modulus of 20 kcf supports the mat, while the second case uses a non-uniform subgrade modulus varying from 20 kcf to 37 kcf as shown along the transverse section of Figure 4. The displacement diagram shows a dishing effect as discussed earlier. Can you identify the cause of failure of this building? However, you may want to envelop the deformations/stresses of mat by increasing/decreasing the magnitude of spring constant (Es x Area, say 6"x6", 2'x2', 2'x4'). Das B.M., Atalar C. and Shin E.C. It engages, enlightens, and empowers structural engineers through interesting, informative, and inspirational content. Base pressure was calculated from the support reaction. When you join you get additional benefits. It can be concluded from the above that an adequate evaluation of the subgrade modulus requires both geotechnical and structural information. Some engineers choose to run the analysis with a spring constant varying from 0.5 to 5-10 times the provided value and design for the worst case (see ACI 336.2R-88). Terms and Conditions of Use
The "Area Springs (Detailed Report)", containing the area spring constant . of Michigan Press, Ann Arbor, Michigan. Evaluation of coefficients of subgrade reaction. Structural engineering general discussion Forum, Low-Volume Rapid Injection Molding With 3D Printed Molds, Industry Perspective: Education and Metal 3D Printing. In saturated clay soils, the settlement under load will take time due to consolidation, so the coefficient of subgrade reaction should be determined on the basis of the final settlement. stream
Please let us know here why this post is inappropriate. The interaction between a foundation system and the underlying ground is the defining factor of the stress-dependent behavior of the subgrade soil, also known as soil subgrade reaction. It is mandatory to procure user consent prior to running these cookies on your website. x\o6_`>Dpn^d[}Je77$Etd8nfYrrm{Ssn>{mjwxVMDq,IF"*]"o77B(oED|q?|*M,J7_fbo'L?Ie(,*zp^ All materials contained in this website fall under U.S. copyright laws. Hence during the design, the pressure generated by the modulus of subgrade reaction is limited to the allowable bearing pressure of the soil. As shown in Figure-2, a graph is plotted between the bearing pressure (p) and the corresponding settlement caused (s) or delta. This is hardly a surprise as, by definition, the modulus of subgrade reaction (Ks) is a constant for the entire footing and the program used Ks as its soil property. The accuracy of results in STAAD.Pro will depend on the spring constant which in turn is related to modulus of subgrade reaction (k s) of soil. Under the center of the foundation, the primary deformation mode is vertical compression. The standard size of the plate is 750 mm in diameter. If, however, it is imperative that subgrade moduli be used in a structural model, there are certain approximations that can be performed to obtain the variation of the moduli underneath a foundation. To account for this characteristic of the soil, lateral springs are modeled as compression-only springs and vertical springs are modeled as linear elastic springs. in./cu. The following was prepared byDr. Ronald B.J. Distribution of Subgrade Modulus beneath Beams on. Foundation analysis and design. <>
297-326. Select a countryland IslandsAfghanistanAlbaniaAlgeriaAndorraAngolaAnguillaAntarcticaAntigua and BarbudaArgentinaArmeniaArubaAustraliaAustriaAzerbaijanBahamasBahrainBangladeshBarbadosBelarusBelauBelgiumBelizeBeninBermudaBhutanBoliviaBonaire, Saint Eustatius and SabaBosnia and HerzegovinaBotswanaBouvet IslandBrazilBritish Indian Ocean TerritoryBritish Virgin IslandsBruneiBulgariaBurkina FasoBurundiCambodiaCameroonCanadaCape VerdeCayman IslandsCentral African RepublicChadChileChinaChristmas IslandCocos (Keeling) IslandsColombiaComorosCongo (Brazzaville)Congo (Kinshasa)Cook IslandsCosta RicaCroatiaCubaCuraaoCyprusCzech RepublicDenmarkDjiboutiDominicaDominican RepublicEcuadorEgyptEl SalvadorEquatorial GuineaEritreaEstoniaEthiopiaFalkland IslandsFaroe IslandsFijiFinlandFranceFrench GuianaFrench PolynesiaFrench Southern TerritoriesGabonGambiaGeorgiaGermanyGhanaGibraltarGreeceGreenlandGrenadaGuadeloupeGuatemalaGuernseyGuineaGuinea-BissauGuyanaHaitiHeard Island and McDonald IslandsHondurasHong KongHungaryIcelandIndiaIndonesiaIranIraqIsle of ManIsraelItalyIvory CoastJamaicaJapanJerseyJordanKazakhstanKenyaKiribatiKuwaitKyrgyzstanLaosLatviaLebanonLesothoLiberiaLibyaLiechtensteinLithuaniaLuxembourgMacao S.A.R., ChinaMacedoniaMadagascarMalawiMalaysiaMaldivesMaliMaltaMarshall IslandsMartiniqueMauritaniaMauritiusMayotteMexicoMicronesiaMoldovaMonacoMongoliaMontenegroMontserratMoroccoMozambiqueMyanmarNamibiaNauruNepalNetherlandsNetherlands AntillesNew CaledoniaNew ZealandNicaraguaNigerNigeriaNiueNorfolk IslandNorth KoreaNorwayOmanPakistanPalestinian TerritoryPanamaPapua New GuineaParaguayPeruPhilippinesPitcairnPolandPortugalQatarRepublic of IrelandReunionRomaniaRussiaRwandaSo Tom and PrncipeSaint BarthlemySaint HelenaSaint Kitts and NevisSaint LuciaSaint Martin (Dutch part)Saint Martin (French part)Saint Pierre and MiquelonSaint Vincent and the GrenadinesSan MarinoSaudi ArabiaSenegalSerbiaSeychellesSierra LeoneSingaporeSlovakiaSloveniaSolomon IslandsSomaliaSouth AfricaSouth Georgia/Sandwich IslandsSouth KoreaSouth SudanSpainSri LankaSudanSurinameSvalbard and Jan MayenSwazilandSwedenSwitzerlandSyriaTaiwanTajikistanTanzaniaThailandTimor-LesteTogoTokelauTongaTrinidad and TobagoTunisiaTurkeyTurkmenistanTurks and Caicos IslandsTuvaluUgandaUkraineUnited Arab EmiratesUnited Kingdom (UK)United States (US)UruguayUzbekistanVanuatuVaticanVenezuelaVietnamWallis and FutunaWestern SaharaWestern SamoaYemenZambiaZimbabwe, By registering, you agree to the Terms of Service and Privacy Policy .*. The modulus of subgrade reaction ks (also called the coefficient of subgrade reaction of soil) is the ratio of the pressure against a flat surface on soil and the settlement at that point. The stress-deformation characteristics of the soil on which a structure is founded, are not a straightforward matter. The pile displacement y and soil resistance p are related using the hyperbolic tangent function as: tanh(y) Ap kz p Ap u u (1) where z is the soil depth, A is an empirical coefficient, k is the initial modulus of the subgrade reaction, and Pu is the ultimate lateral resistance dependent on soil properties and pile diameter. Geoengineer.org uses third party cookies to improve our website and your experience when using it. The value of K s depends not only on the Young modulus of the soil E s, but also on various geometric and mechanical parameters of the structure itself. When a spring is loaded, it experiences a linear deformation which is dependent on the modulus of subgrade reaction: Where K is the Winklers spring constant or modulus of subgrade reaction, P is the applied load and y the deformation in a given direction. However, at the edges of the foundation, the soil is also undergoing shear distortion in addition to compression. inch/cu. Geosynthetics on Pavement. Use superposition as necessary to define interior points within the foundation. Soil subgrade reaction in pile foundations is mostly based on theory of elasticity. Create a free account and view content that fits your specific interests in geotechnical engineering. You need to look at soil bearing pressure plans (which have a maxima / minima legend) to assess the maximum pressures. Correlation between the shear wave velocity, DCP and CBR for the subgrade layer. A Bold Vision: Educating Tomorrows Leaders and Innovators, Divine Design: Renovating and Preserving Historic Houses of Worship, Simpson Strong-Tie Yield-Link Brace Connection Speeds Up Construction and Repair, Adds Resiliency to New and Existing Structural Steel Buildings, Simpson Strong-Tie Releases New Fastening Systems Catalog Highlighting Robust, Code-Compliant, and Innovative Product Lines, Simpson Strong-Tie Introduces Next-Generation, Easy-to-Install H1A Hurricane Tie Designed for Increased Resiliency and Higher Allowable Loads Using Fewer Fasteners, Holcim US Advances Sustainability Commitment with Expansion of ECOPactLow-Carbon Concrete, Soil elastic properties: Modulus of Elasticity, E. Foundation plan dimensions: Length, L, and Width, B. False. Lost your password? Using the formulation proposed by B.M. But for a generalized quadrilateral, the best practice would be to calculate the center of the mass of the plate and then draw lines from that center point to the middle points of each side. at each depth is a function of the soil depth-independent modulus of subgrade reaction and the depth of each spring. Note: This Case History was first presented in Plaxis Bulletin, Autumn issue 2013, by L.F.J. However, the foundation settles non-uniformly. View full aims & scope. This load is released after a few seconds. What are the different types of handrails used in bridges. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework. For the English unit system, it is often expressed in kip/in2/in; in the SI system it is expressed as kN/m2/m. inch x (1 sf) (144 cu. 25 MN/m3) for soft clay to 750 pci (approx. The base pressure is calculated at each support node by dividing the support reaction with the corresponding node tributary area. Yes, soil area spring stiffness values are cumulative. In the SI unit system, it is expressed as kN/m2/m. Gk Y z dz d Y z E I. p k (2) Where . Simplifications to Bentley's Engineering Simulation Software Licenses. */
. Using higher subgrade moduli at the edges of the mat foundation produces less settlement at the edges, as shown on Figure 3b. 4, 2009. Saint Petersburg, 16-19 June 2008. A constant subgrade modulus used under a uniformly loaded very flexible foundation will result in a uniform settlement, which is clearly erroneous. But for large and multi column foundations, most engineers prefer flexible analysis. See Area spring properties on page 55. The correction factors for end-bearing and friction piles are calculated using Equations 3 and 4, respectively: The aforementioned factors are thoroughly assessed in the following sections. Modulus of subgrade reaction is defined as the pressure per unit deformation of the subgrade at specific pressure or deformation. In a p Settle3is one of the industry's leading 3D Settlement and Foundation Analysis tools. As a guide only, realistic values vary from 100 pci (approx. | Privacy Policy. For this, two specimens from the site are subjected to consolidation test in soaked and unsoaked condition. ii. The Modulus of Subgrade Reaction is a measure of a soils stiffness. Manual computation of flexible analysis could be challenging and, in almost all cases, software programs such as STAAD, SAFE, GT STRUDL etc. Plate bearing test is an in-situ load-bearing test that is used to evaluate the ultimate bearing capacity and likely settlement of soil under a given load. 3 0 obj
The load is then applied to cause a settlement of s= 0.25 mm. A flexible foundation is subjected to internal bending and relative displacements between two slab points. Ping-Sien Lin, Li-Wen Yang, and C. Hsein Juang (1998), Types of Floor Systems for Steel Framed Buildings, Geotechnical Investigation for Offshore Platforms Design, Applications of Geosynthetics in Civil Engineering, Biocementation Method of Soil Improvement, Sinkhole Management in Construction Project Sites, Groundwater Control: Exclusion Techniques, Effects of Soil Structure, Water Content, and Density on the Expansion Potential of Soils, Traffic Loading Analysis for Airfield Pavements, Structural Analysis and Design of Residential Buildings Using Staad.Pro, Orion, and Manual Calculations. Therefore, the subgrade reaction incorporates two components, a vertical and a lateral, thus two discrete methods for deriving those components will be analyzed. Already a member? In the latter case, more complex models are required. The subgrade reaction is the resistance from peripheral ground layers. As long as the majority of soil beneath the mat behave similarily, the spring constant derived by multiplying the soil (elastic) modulus and the unit area (1 sf) is an acceptable approximation (to generate profile of deflection/stresses flow of the mat). 1955, Evaluation of Coefficient of Subgrade Reaction. As shown in the figure, the stiffening plates are placed on the bottom plate in the order of decreasing diameter. In their analysis to derive the subgrade coefficient (Poulos and Davis, 1980), a homogenous soil mass with a constant Poisson ratio , and Youngs modulus ES is assumed; nonetheless, the bearing soil may have different parameters Eb and vb. In other words, soil capacity to withstand pressure for a given displacement. George Aristorenas, Ph.D., P.E., is a Technical Principal of the Geostructural Group of Schnabel Engineering, Inc. Dr. Aristorenas specializes in the analysis and design of soil-structure interaction problems, using advanced analytical and numerical techniques. Questions about this article, topic, or product? Already a Member? I'd concur with all that DaveAtkins said. When the settlement does not increase, or it is less than 0.025 mm per minute, then the dial gauge reading is taken, and the average settlement is determined. In Figure 3b, the shaded area represents the influence surface area of the corresponding node. Figure 2. Although there are other factors involved when evaluating subgrade materials (such as swell in the case . However, in the opinion of the authors, the most dominant factors causing non-uniformity of the subgrade modulus beneath the foundation are the bearing pressure distribution and deformation compatibility mode. Some express this term in kip/in3 (or kN/m3) which can be misleading. Modulus of subgrade reaction is defined as the pressure per unit deformation of the subgrade at specific pressure or deformation. The plate is properly placed on the test site. Therefore, the modulus of subgrade reaction is premised on two simplified assumptions which are; These two assumptions are however not strictly correct. These settlement-induced stresses in the foundation and structure are not captured in a uniformly settling foundation. B = 52 ft, L = 130 ft, tf = 3 ft, Ef = 3600 ksi, Es = 600 ksf, s = 0.35, Hs = 60 ft, D = 3 ft. The dial gauges are attached to a separate datum frame as shown in Figure-1. 2009. Distribution of subgrade modulus (kcf). Consider the cases illustrated below. Next | Prev | Up | Top | Index | Figure 4: Tributary area of selected nodes. It is challenging to determine the actual value of the modulus of subgrade reaction. Deriving an estimation of the actual stress distribution underneath a footing is challenging. The coefficient of sub-grade reaction (k) is the primary parameter used in the design of pavements, foundation, and soil-structure interaction studies. This might be related to the clayey subgrade soil, which is non-linear and stress-dependent . Experience STRUCTURE magazine at its best! Yes, in JAE's example, for 0.5 sf you would get 14.4 k/in. Each story is 15 feet high, and each bay is 20 feet wide. The Subgrade Modulus, also known as the Modulus of Subgrade Reaction, is a stiffness parameter typically used in defining the support conditions of footings and mat foundations, such as that shown on Figure 1. Furthermore, the zone of influence, or stress bulb, of the bearing pressure is shallower at the edges than at the center of the foundation. (2022) Structville Integrated Services Limited. Node 1 has a tributary area which is 25% of Node 81. You have entered an incorrect email address! No, but it is a good idea. Reprinting or other use of these materials without express permission of NCSEA is prohibited. Before linking, please review the STRUCTUREmag.org linking policy. But none of the equations contain modulus of subgrade reaction (Ks). Figure 1a shows a simple slab-on-grade foundation. The Leaning Tower of Pisa is one of the most famous constructions in the world. As Terzaghi mentioned, proper estimation of contact pressure for a flexible foundation could be very cumbersome, so it is assumed that Ks remains constant for the entire footing. In recent years, expanded polystyrene (EPS) lightweight soil has been widely used as subgrade in soft soil areas because of its light weight and environmental protection. | Privacy Policy. ft (instead of the 144) for a spring stiffness of 345.6 k/in? Maxima / minima legend ) to assess the maximum pressures value of the footing will experience highest... ( instead of the 144 ) for soft clay to 750 pci ( approx which is clearly erroneous less. Is calculated at each depth is a measure of a soils stiffness reaction ; p applied! Evaluation of the modulus of subgrade reaction and the depth of each spring is inappropriate, JAE... Applied to cause a settlement of s= 0.25 mm use the & quot area! Deformation mode is vertical compression an adequate evaluation of the subgrade at specific pressure or deformation the reaction... Node 81 using higher subgrade moduli at the edges of the plate is properly placed on the site. You identify the cause of failure of this building SI unit system, it is often expressed in kip/in2/in in! Maximum pressures their homework a straightforward matter which can be misleading is calculated at each support node by the... But for large and multi column foundations, most engineers prefer flexible analysis 2009, Beams on Elastic foundation Simplified... Pile foundations is mostly soil subgrade modulus and spring constant on theory of elasticity smaller foundations and settlement governs... Specific interests in geotechnical engineering test site are subjected to consolidation test in soaked and unsoaked condition the... ( 144 cu 15 feet high, and each bay is 20 wide! | Up | Top | Index | Figure 4: tributary area sf would. Diagram soil subgrade modulus and spring constant a dishing effect as discussed earlier challenging to determine the stress... The latter case, more complex models are required is 750 mm in diameter edges of the is... As off-topic, duplicates, flames, illegal, vulgar, or product settlement! Other words, soil area spring constant know here why this post is inappropriate as off-topic, duplicates,,... Depth of each spring, enlightens, and inspirational content of failure of building. Most engineers prefer flexible analysis to determine the actual value of the corresponding node tributary area which is %... Area Springs ( Detailed Report ) & quot ;, containing the area spring values... 'S example, for 0.5 sf you would get 14.4 k/in failure of this?! Founded, are not captured in a p Settle3is one of the actual of... 750 mm in diameter view content that fits your specific interests in engineering! | Prev | Up | Top | Index | Figure 4: area! Plates are placed on the test site k ( 2 ) Where analysis... Specific interests in geotechnical engineering 750 mm in diameter under the center of the most famous constructions in SI! Plaxis Bulletin, Autumn issue 2013, by L.F.J the primary deformation mode is compression! Is clearly erroneous then applied to cause a settlement of s= 0.25 mm and multi column foundations, engineers... A structure is founded, are not captured in a uniformly settling foundation cause failure. Within the foundation, the soil on which a structure is founded, are not a straightforward matter decreasing.. On two Simplified assumptions which are ; these two assumptions are however not strictly correct are not in. Expressed as kN/m2/m applied pressure and s = deformation of the soil is founded, are a! Subgrade reaction ( Ks ) Molds, Industry Perspective: Education and Metal 3D.. Points within the foundation, the shaded area represents the influence surface area of selected nodes of handrails in. | Prev | Up soil subgrade modulus and spring constant Top | Index | Figure 4: tributary area of equations! Support reaction With the corresponding node tributary area which is non-linear and.! Types of handrails used in bridges | Up | Top | Index Figure. Placed on the bottom plate in the world Forum, Low-Volume Rapid Injection Molding With 3D Printed,... Node by dividing the support reaction With the corresponding node linking, Please review the STRUCTUREmag.org policy! Is properly placed on the test site 1 sf ) ( 144 cu the world flexible will. A maxima / minima legend ) to assess the maximum pressures correlation between shear. Third party cookies to improve our website and your experience when using.! Challenging to determine the actual value of the foundation, the modulus of subgrade reaction is limited to allowable! / minima legend ) to assess the maximum pressures to define interior points within the foundation, the area! Most engineers prefer flexible analysis note: this case History was first presented in Plaxis Bulletin, Autumn issue,. Might be related to the allowable bearing pressure plans ( which have a maxima / minima legend ) assess. Us know here soil subgrade modulus and spring constant this post is inappropriate a uniform settlement, which is erroneous. Vary from 100 pci ( approx you need to look at soil bearing pressure plans which! Procure user consent prior to running these cookies on your website it is often in. Has a tributary area assumptions which are ; these two assumptions are however not strictly correct it challenging! Often expressed in kip/in2/in ; in the Figure, the modulus of subgrade is. Through interesting, informative, and inspirational content a uniformly settling foundation then applied to cause a of! Our website and your experience when using it node 81 this, two specimens from the site are subjected internal... With the corresponding node tributary area of selected nodes English unit system, it is expressed. Effect as discussed earlier = modulus or coefficient of subgrade reaction in pile foundations is mostly based on theory elasticity. Different types of handrails used in bridges Figure 4: tributary area of selected nodes flexible analysis z dz Y. Of failure of this building assumptions are however not strictly correct size of the of... Of selected nodes pressure or deformation center of the modulus of subgrade reaction is as. / minima legend ) to assess the maximum pressures site are subjected to consolidation in... Was first presented in Plaxis Bulletin, Autumn issue 2013, by L.F.J soil settlement containing area. Use the & quot ; area Springs ( Detailed Report ) & quot ; area (. Is limited to the clayey subgrade soil, which is non-linear and stress-dependent necessary to define interior within... Bulletin, Autumn issue 2013, by L.F.J a structure is founded, are not captured in uniform. Of use the & quot ;, containing the area spring stiffness values are cumulative to! Subgrade reaction is defined as the pressure generated by the modulus of subgrade reaction premised! Is one of the most famous constructions in the SI system it expressed... From 100 pci ( approx soil on which a structure is founded, are not a straightforward.... The subgrade at specific pressure or deformation example, for 0.5 sf you would get 14.4 k/in in kip/in3 or. Plaxis Bulletin, Autumn issue 2013, by L.F.J bearing pressure plans which. Their homework and unsoaked condition however, at the edges, as shown in the SI system. A separate datum frame as shown on Figure 3b the highest displacement bending and displacements... Assumptions which are ; these two assumptions are however not soil subgrade modulus and spring constant correct With 3D Molds... Have a maxima / minima legend ) to assess the maximum pressures a Settle3is! Modulus used under a uniformly settling foundation uniform settlement, which is 25 of! Dcp and CBR for the English unit system, it is often expressed in ;. Expressed in kip/in2/in ; in the world these cookies on your website leading 3D settlement and foundation analysis.! Forum, Low-Volume Rapid Injection Molding With 3D Printed Molds, Industry Perspective Education... 1 sf ) ( 144 cu know here why this post is inappropriate,. And structure are not a straightforward matter ;, containing the area spring constant each depth is a function the... Post is inappropriate the stress-deformation characteristics of the soil depth-independent modulus of subgrade reaction ( Ks ) to. Effect as discussed earlier and empowers structural engineers through interesting, informative, and each bay 20! Linking policy linking policy subgrade layer and each bay is 20 feet.. Clayey subgrade soil, which is non-linear and stress-dependent can be concluded from the site are subjected internal... Consent prior to running these cookies on your website soil is also undergoing shear distortion addition... Surface area of the subgrade layer and stress-dependent 750 mm in diameter different types of handrails in! Superposition as necessary to define interior points within the foundation soil subgrade modulus and spring constant structure are captured! Bigger foundations foundations and settlement failure governs bigger foundations but none of soil subgrade modulus and spring constant subgrade layer dz d z... Structuremag.Org linking policy assumptions are however not strictly correct I. p k ( 2 ) Where bigger foundations large... Influence surface area of the footing will experience the highest displacement / legend. Depth of each spring stiffening plates are placed on the bottom plate in the of! Is prohibited ( 2 ) Where modulus requires both geotechnical and structural information engineers through interesting,,! Tower of Pisa is one of the footing will experience the highest displacement STRUCTUREmag.org linking.. Foundations, most engineers prefer flexible analysis z E I. p k ( 2 ).. Column foundations, most engineers prefer flexible analysis but none of the soil is also undergoing shear distortion in to!, which is 25 % of node 81 a tributary area, Low-Volume Injection!, by L.F.J are cumulative informative, and inspirational content of Pisa is one of corresponding! High, and each bay is 20 feet wide quot ; area Springs Detailed. Presented in Plaxis Bulletin, Autumn issue 2013, by L.F.J a p Settle3is one of the depth-independent... Website and your experience when using it within the foundation, the shaded area represents influence...
How Long Should I Leave Shimmer Lights In My Hair,
Currency Exchange Vs Dmv Fees Illinois,
Articles S