In theory, could be any value from 0 to 1 however, in design, it is typical for the coefficient of friction to be taken as 0.5. Solution. Machine Design Apps Best regards, Partha Roy Manager (Engineering Design); NMSEZ Pvt Ltd (Reliance Industries Ltd) Mobile No. Login. Heat Transfer tgbt ieveofps cetweem tge hfumibtlfm sflo bmi tge hfftlma. The unit weight of the concrete is 24 kN m3 and the soil has unit weight 18 kN m3. The coke is combined with limestone and ore to the . 24-29. clean fine sand, silty or clayey fine to medium sand. thank you. Calculate the Moment Capacity of an Reinforced Concrete Beam, Reinforced Concrete vs Prestressed Concrete, A Complete Guide to Building Foundations: Definition, Types, and Uses. Considering cases of higher and lower coefficients of friction we were able to discuss discussed what kind of effects this would have on trying to push an object across the floor. It is usually observed between one solid and one wet surface. The friction force, F, is proportional to the normal force, N, and the coefficient of friction, : where s is the coefficient of static friction and k is the coefficient of kinetic friction. Thank you for helping keep Eng-Tips Forums free from inappropriate posts.The Eng-Tips staff will check this out and take appropriate action. Then we must choose an appropriate coefficient of friction, to final the final frictional force. *Eng-Tips's functionality depends on members receiving e-mail. The stop distance is not dependent on the mass of the car. Static frictional coefficients are used for objects without relative motion. Beam Deflections and Stress C E192086 Pages: 2. undrained shear strength of 99kPa. This might be increased up to 2/3 which (in most cases) will cause the calculation to be less conservative. This discussion is somewhat dangerous as for clays, who's to say that the ultimate strength will be based on long-term "drained" loading conditions (as referenced by jmgray. The manufacturer's number is slightly less than the values given by the Portland Cement Association (PCA) and Precast/Prestressed Concrete Institute (PCI). What is a Column Interaction Diagram/Curve? Typical and assumed distributions of concrete lateral pressure. The frame and the edge of the door sliding against one another. See Thread592-11538 for simlar query and responses. would have a reduction factor applied. Both the types of COF can be expressed by the same equation as below (refer with the Fig.1): N Normal reaction perpendicular to the surface. Although, reliable sources (mentioned at the reference section) has been used for compiling the above COF table but still the values shown are approximate only. For the purpose of exploring the soil slope instability mechanism, this paper takes a slope in Yunda Road, Chenggong, Kunming, as case study and establishes a slope model utilizing FLAC 3D coupled with Geo-studio software. Thermodynamics Check out these structural calculators: Beam Analysis Bolted Joints Lug Analysis Column Buckling. The Coefficient Of Static Friction Between The 300 Kg Crate upload Herison z Hayda 1/2 Downloaded from appcontent.compassion.com on December 20, 2022 by Herison z Hayda . Just for a moment, lets give a value of 1 essentially removing it from the equation. s r.o., All rights reserved |, Table of Ultimate Friction Factors for Dissimilar Materials | Influence of Friction between Soil and back of the Structure | GEO5 | Online Help, Influence of Friction between Soil and back of the Structure, Table of Ultimate Friction Factors for Dissimilar Materials, Copying and Pasting Soils and Rigid Bodies, Modification of Template During Data Input, (3) Parameters for Input File Splitting into Columns, Analysis According to the Safety Factor (ASD), Analysis According to the Theory of Limit States (LSD), Analysis of Foundations (Spread Footing, Piles), LRFD - Analysis of Retaining Walls (Support Structures), Restrictions on the Optimization Procedure, Terrain - Plane and Polygonal Slip Surface, Surcharge - Plane and Polygonal Slip Surface, Anchors - Plane and Polygonal Slip Surface, Vertical Bearing Capacity - Analytical Solution, Vertical Bearing Capacity - Spring Method, Settlement - Linear Load-Settlement Curve (Poulos), Settlement - Non-Linear Load-Settlement Curve (Masopust), Horizontal Bearing Capacity - Elastic Subsoil (p-y Method), Horizontal Bearing Capacity - Brom's Method, Settlement - Cohesionless Soil (Load-Settlement Curve), Calculation of Winkler-Pasternak Constants from Deformation Parameters of Soils, Calculation of Winkler-Pasternak Parameters C1 and C2 from Geological Profile, Definition of Construction Site using the GPS, Data Transfer from the "Point Cloud" program, Relation between Field Test, Soil Profile and Borehole, Creation of Soil Profile using Classification of Soils, Creation of Soil Profile from an SPT, DPT or PMT, Creation of Geological Section from the Geological Model, Geological Model with Layers Following the Terrain, Modification of the Final 3D Model Using Boreholes, Copying data from the Stratigraphy program to other GEO5 programs, Principle of Numerical Solution of Consolidation, Numerical Implementation of MCC and GCC Models, Boundary Conditions in Dynamic Analysis of Earthquake, Material Parameters in Earthquake Analysis, Loss of Convergence of Nonlinear Analysis, Eigenvalue analysis - calculation of eigenfrequencies and eigenmodes, Setting Basic Parameters of Slope Stability Analysis, Setting Driving Parameters of Relaxation of Reduction Factor, Increment of Earth Pressure due to Surcharge, Increment of Earth Pressure under Footing, Active Earth Pressure - The Mazindrani Theory (Rankine), Active Earth Pressure - The Coulomb Theory, Active Earth Pressure - The Mller-Breslau Theory, Active Earth Pressure - The Caquot Theory, Passive Earth Pressure - The Rankine and Mazindrani Theory, Passive Earth Pressure - The Coulomb Theory, Passive Earth Pressure - The Caquot - Krisel Theory, Reduction Coefficient of Passive Earth Pressure, Passive Earth Pressure - The Mller - Breslau Theory, Passive Earth Pressure - The Sokolovski Theory, Passive Earth Pressure - SP 22.13330.2016, Earth Pressure at Rest for an Inclined Ground Surface or Inclined Back of the Structure, Distribution of Earth Pressures in case of Broken Terrain, Without Ground Water, Water is not Considered, Hydrostatic Pressure, Ground Water behind the Structure, Hydrostatic Pressure, Ground Water behind and in front of the Structure, Surface Surcharge - Active Earth Pressure, Trapezoidal Surcharge - Active Earth Pressure, Concentrated Surcharge - Active Earth Pressure, Increment of earth pressure due to horizontal surcharge, Surface Surcharge - Earth Pressure at Rest, Trapezoidal Surcharge - Earth Pressure at Rest, Concentrated Surcharge - Earth Pressure at Rest, Surface Surcharge - Passive Earth Pressure, Forces from Earth Pressure at Rest Acting on the Rigid Structure, Influence of Earthquake according to Chinese Standards, Influence of Earthquake according to JTJ 004-89, Influence of Earthquake according to JTS 146-2012, Influence of Earthquake according to SL 203-97, Seismic Fortification Intensity according to Chinese Standards, Water Influence according to Chinese Standards, Importance Coefficient for Seismic Design Ci, Adjusting Coefficient for Seismic Bearing Capacity a, Evaluation of Forces in the Footing Bottom, Internal Stability of a Gabion Wall - Safety Factor, Internal stability of a Gabion Wall - Limit States, Analysis of Bearing Capacity of the Nails, Automatic Calculation of the Coefficient of Pressure Reduction Below Ditch Bottom, Analysis of Anchored Wall Simply Supported at Heel, Modulus of Subsoil Reaction According to Schmitt, Modulus of Subsoil Reaction According to Chadeisson, Modulus of Subsoil Reaction According to CUR 166, Modulus of Subsoil Reaction Determined from Iteration, Modulus of Subsoil Reaction According to Menard, Modulus of Subsoil Reaction According to NF P 94-282, Modulus of Subsoil Reaction Specified by Dilatometric Test (DMT), Modulus of Subsoil Reaction According to Chinese standards, Verification of Ditch Bottom according to Chinese Standards, Upheavel Check according to Chinese Standard, Heave Check according to Chinese Standard, Piping Check according to Chinese Standard, Terrain Settlement behind the Shoring Structure, Determination of Forces Acting on an Anti-Slide Pile, Distribution of Pressures Above the Slip Surface, Calculation of passive force in subsequent stage, Calculation of Internal Forces on a Shaft (Dimensioning), Earthquake Analysis According to GB 50111-2006, Earthquake Analysis According to NB 35047-2015, Earthquake Analysis According to GB 50330-2013, Earthquake Analysis According to JTG B02-2013, Analysis According to the Theory of Limit States / Safety Factor, ITF Method (Imbalance Thrust Force Method), Changing the Inclination of Dividing Planes, Influence of Water Acting on Slip Surface, Own Water Force Acting Only on Slip Surface, Verification According to the Factor of Safety, Verification According to the Theory of Limit States, Extensible Reinforcements - Active Earth Pressure, Inextensible Reinforcements - Combination of Earth Pressures, Bearing Capacity of Foundation on Bedrock, Analysis According to EC 7-1 (EN 1997-1:2003), Parameters to Compute Foundation Bearing Capacity, Horizontal Bearing Capacity of Foundation, Determination of Cross-Sectional Internal Forces, Verification According to the Safety Factors, Coefficient of Increase of Limit Skin Friction, Correction Factor for Soil Poisson's Ratio Rv, Correction Factor for Stiffness of Bearing Stratum Rb, Base-Load Proportion for Incompressible Pile BETAo, Correction Factor for Pile Compressibility Ck, Correction Factor for Poisson's Ratio of Soil Cv, Correction Factor for Stiffness of Bearing Stratum Cb, Correction Factor for Pile Compressibility Rk, Correction Factor for Finite Depth of Layer on a Rigid Base Rh, Constant Distribution of Modulus of Subsoil Reaction, Modulus of Subsoil Reaction According to CSN 73 1004, Modulus of Subsoil Reaction According to Matlock and Reese, Modulus of Subsoil Reaction According to Vesic, Pile Horizontal Bearing Capacity - Broms Method, Determination of Equivalent Average Cone Tip Resistance, Determination of Average Cone Tip Resistance, Coefficient of Influence of Pile Widened Base BETA, Coefficient of Reduction of a Pile Base Bearing Capacity ALFA p, Correlation Coefficients for Evaluating of Bearing Capacity of Piles from CPTs, Verification According to the Safety Factor, Cohesionless Soil (Analysis for Drained Conditions), Cohesive Soil (Analysis for Undrained Conditions), Analysis According to the Theory of Limit States, Calculation of Stiffness of Vertical Springs, Bearing Capacity of Cross Section Loaded by Normal Force, Bearing Capacity of Cross Section Loaded by Combination of Bending Moment and Normal Force, Constant A Reflecting the Type of Support in the Micropile Head, Modulus of Horizontal Reaction of Subsoil, Calculation of the Modulus of Horizontal Reaction of Subsoil Er, Values of the Modulus of Subsoil Reaction Ep, Bearing Capacity of the Micropile Root Section, Coefficients of Type of Application of Micropile, Skin Friction and Bearing Capacity of the Micropile Root in Rock, Skin Friction of the Micropile Root - Graphs, Classification of Soils According to Robertson, Coefficient of Penetrometer (Net Area Ratio), Overall Settlement and Rotation of Foundation, Influence of Foundation Depth and Incompressible Subsoil, Analysis According to NEN (Buismann, Ladd), Analysis for Overconsolidated Sands and Silts, Analysis for Overconsolidated Cohesive Soils, Settlement Analysis Using DMT (Constrained Soil Modulus), Determination of the Influence Zone Depth, Method of Restriction of the Primary Stress Magnitude, Overconsolidation Index of Secondary Compression, Recommended Values of Parameters for Volume Loss Analysis, Coefficient of Calculation of Inflection Point, Subsidence Trough with Several Excavations, Verification of Rectangular Cross Section Made of Plain Concrete, Verification of Rectangular RC Cross Section, Verification of Circular RC Cross Section, Verification of Spread Footing for Punching Shear, Design of Longitudinal Reinforcement for Slabs, Verification of Rectangular Cross Sections Made of Plain Concrete, Concrete Cross Section with Steel Profile Verification. Distribution of earth pressure along the structure for = 0. The friction coefficient value changes not only with material but also with the position and orientation of the participating materials. Other interface materials (precast concrete, etc.) By joining you are opting in to receive e-mail. Coefficients of friction are sensitive to atmospheric dust and humidity, oxide films, surface finish, velocity of sliding, temperature, vibration, and extent of contamination. The unique geological conditions in Yunnan make it likely for landslides to occur there. Please check whether your browser is not blocking reCAPTCHA. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework. The basic raw materials are coal, iron ore, limestone and various chemicals. = static (s) or kinetic (k) frictional coefficient, N = normal force between the surfaces (N, lb), There are at least two types of friction forces. Friction Design Data. These effects are combined into the influence of Normalized Roughness of the interfaces. Shear Strength of High-Strength ConcreteACI 318-95 versus Shear Friction. Sliding Stability, Coefficient of friction given soils angle of internal friction, Structural engineering general discussion Forum, https://www.eng-tips.com/viewthread.cfm?qid=442513, Low-Volume Rapid Injection Molding With 3D Printed Molds, Industry Perspective: Education and Metal 3D Printing. We were unable send the link to your email. Friction is a resisting force that is generated when two bodies interact, typically one sliding across the other. Alternative Energy (current) . Note that static coefficients are somewhat higher than the kinetic or sliding coefficients. Coefficient of Friction Equation and Table Chart Design Resources Friction Design Data The frictional force for Static Friction can be expressed as: F max = F n where F max = Frictional force (N, lb) = static ( s ) or kinetic ( k ) frictional coefficient F n = Applied Normal force (N, lb) embedded in Limestone Layer C or placed on the concrete fill is 0.60. If the total weight of our box was 1 kN then so is the frictional force. So, if you need accurate COF value, you must obtain it by experiment only. The static and kinetic friction coefficient values reference table shown in this article will be helpful for finding the COF values of commonly used materials. Table 1: Coefficients of Friction of Various Roadway Surfaces (Noon, 1994) Surface Type Coefficient of Friction () Gravel and dirt road 0.35 Wet, grassy field 0.20 Dry asphaltic concrete 0.65 Wet asphaltic concrete 0.50 Dry concrete 0.75 Wet concrete 0.60 Snow 0.20-0.25 Ice 0.10-0.15 Loose moist dirt that allows tyre to sink about 5 cm Grade of concrete M 20 (Fixed) 8. How to Determine the Reactions at the Supports? It should be noted that there can be significant differences between static friction (typically higher) and kinetic (sliding) friction Amontons's Laws of Dry Friction Login. 0.0 0.2 0.4 0.6 0.8 1.0 1.2 0.7 0.8 0.9 1.0 1.1 1.2 1.3 Peak friction coefficient f s Mean particle size D 50 (mm) In case of an uncertainty it is always safer to assume smaller vale of . Soils are sandy (cohesion = 0). 3. A coefficient of friction for cast-in-place concrete to soil is =tan(0.7*phi') or =tan(0.7*phiT) depending on site conditions & rate of loading. The friction force, F, is proportional to the normal force, N, and the coefficient of friction, : where s is the coefficient of static friction and k is the coefficient of kinetic friction. Close this window and log in. Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications! Cast iron on asbestos, fabric brake material, Copyright 2000 - 29 - 31. Fine spol. This means that the frictional force is now equal to the total weight. So in your case 0.666*tan(26) = 0.325. 6 it cancels out. b) Draw reinforcement details of toe and stem with curtailment of reinforcements. We then considered how this phenomenon occurs in Retaining Walls and what it means for us as designers. Coefficients of friction between materials are best determined through testing. Usually, ASTM D1894-14 is the most widely used method for COF measurement. Typically steel on steel dry static friction coefficient 0.8 drops to 0.4 when sliding is initiated - and steel on steel lubricated static friction coefficient 0.16 drops to 0.04 when sliding is initiated. For static COF the block must be in static or non-moving condition, i.e., you have to take the friction force value of the force which is applied to the block for giving motion to it but the force value has not yet reached to the limit that can move the block. We will be using a ring beam foundation with 6" of crushed base in the middle of it. Friction force develops between contacting surfaces of two bodies and acts to resist relative motion between the bodies. Providing the friction between the soil and the back of the wall is considered in the analysis of earth pressures, the earth pressure and also its resultant P are inclined from the back of the wall by the angle . Orientation of friction angles from normal to the back of the wall must be introduced in accord with the mutual movement of the structure and soil. With increased velocity the the friction decrease. Feedback Advertising PCI's Design Handbook says the concrete-to-concrete friction factor for dry conditions is 0.80. All rights reservedDisclaimer | Thanks. See ACI 318 Section 11.7.4.3. These include passive earth pressure, frictional resistance, and active earth pressure. Clean fine to medium sand, silty medium to coarse sand, silty or clayey gravel . Or, for example Aluminum Steel and Steel Aluminum? This is explained by the fact that with an increase in porosity, the area of actual soil contact with the surface of a foreign body decreases, i.e. Friction is a resisting force that is generated when two bodies interact, typically one sliding across the other. The coefficient of friction for concrete on rock is often quoted as 0.30 to 0.4. What is the coefficient of static friction between silicon and graphite? Grade of concrete is M20 and steel is Fe415. This is a very simplistic statement and quite misleading for brake materials. Engineering Standards Typical Coefficient of Friction Values for Common Materials, Click to share on Twitter (Opens in new window), Click to share on Facebook (Opens in new window), Click to share on LinkedIn (Opens in new window), Click to share on WhatsApp (Opens in new window), Click to email a link to a friend (Opens in new window), Your project, our springs Get custom springs for your project delivered anywhere in INDIA, Aromatic Organic Bengali Govindobhog Chini Atop Rice, 6 Steps for Tolerance Calculation of Shaft Drawing with Din ISO 286 IT Grades and Fundamental Deviation Symbol, Five Important Basics of Fatigue Stress Design Calculation, How to do the Stainless Steel Selection for your Application, Maths behind gradient descent for linear regression SIMPLIFIED with codes Part 2, Maths behind gradient descent for linear regression SIMPLIFIED with codes Part 1, Numbers Basics Natural vs Integer vs Rational vs Real, How to Setup and Use Raspberry Pi without an External Monitor, How to Calculate the Free Length of the Helical Compression Spring for your Next Project, ASM-VOL 18-FRICTION, LUBRICATION AND WEAR TECHNOLOGY, Friction Science and Technology FROM CONCEPTS to APPLICATIONS By Peter J. Blau. We generally take tan as the nominal coefficient of friction between foundation soil and granular backfill or concrete cast directly against the foundation soil, using factored loads. These applications will - due to browser restrictions - send data between your browser and our server. coefficient of friction: concrete on concrete, Engineering Codes, Standards & Certifications, Low-Volume Rapid Injection Molding With 3D Printed Molds, Industry Perspective: Education and Metal 3D Printing. The coefficient of friction for concrete on rock is often quoted as 0.30 to 0.4. Static friction is the frictional force generated to prevent any movement between the two bodies whilst kinetic friction is the frictional force generated when the two bodies are in motion. The building was rigidly connected to the reinforced concrete raft. With increasing value of the value of active earth pressure decreases, i.e. Metal 3D printing has rapidly emerged as a key technology in modern design and manufacturing, so its critical educational institutions include it in their curricula to avoid leaving students at a disadvantage as they enter the workforce. We know that the frictional force is the product of and the total contributing weight. Kinetic or sliding frictional coefficients are used with relative motion between objects. It is commonly thought that the static coefficients of friction are higher than the dynamic or kinetic values. at very low velocity between the surfaces the friction is independent of the velocity of rubbing. Concrete on soil look for table 5.5.5 B in AASHTO standard. The friction coefficient value changes not only with material but also with the position and . You might remember from your school physics lessons that there are two classes of friction, static and kinetic. Note! Say our box is made of cardboard and the floor is constructed with timber floorboards. PCI's Design Handbook says the concrete-to-concrete friction factor for dry conditions is 0.80. The results demonstrate a positive correlation between concrete strength and friction coefficient and better performance of shot-blasted steel. Figuring out how to best evaluate phi is the hard part. In my case, we have a rectangular concrete tank, cast against and at grade, holding back full height water pressure and obviously no lateral soil resistance.We have a full length engineering joint that basically divides the tank into pieces, so lateral movement could be possible. When selecting the value of it is necessary to reflect also other conditions, particularly the force equation of equilibrium in the vertical direction. We were unable send the link to your email. Solution for Question 1 What is the value of hydraulic gradient in a 2.2 m diameter smooth concrete pipe carrying a discharge of 3.8 m/sec using Hazen-Williams . Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a parts function at the center of their design considerations. Coefficient of friction is a measure of the amount of friction existing between two surfaces. I think the specification limit of 0.15 is too low for this application. The spacing between the contraction joints of a CC pavement is 3.5 m. Determine the stress developed in the pavement (in kg/cm) due to contraction if the coefficient of friction between the bottom of the pavement and the supporting layer is 1.05 and the unit weight of concrete is 2450 kg/m. 4. The coefficient of static friction for steel is around 0.6-0.15 and the coefficient of kinetic friction is around 0.09-0.6. Coefficient of friction (COF) is a dimensionless number that is defined as the ratio between friction force and normal force (Eqn (2.1)). Grade of concrete M 20 (Fixed) 8. BAPC Pervious Concrete Maintenance Manuel, dated 2013 or newer. Friction - Friction Coefficients and Calculator. It is also dangerous to use those figures in an actual design without doing field testing on the materials to confirm the actual coefficient of friction. The equation at the end of your reply shows that at a depth of 0 ft, the interface friction would be 0. Friction coefficients between different wheel/tire materials and concrete . 4. Although, reliable sources (mentioned at the reference section) has been used for compiling the above COF table but still the values shown are approximate only. For example, static friction can prevent an object from sliding down a sloped surface. One should decide whether the structure is capable of transmitting the vertical surcharge due to friction on its back without excessive vertical deformation. The friction coefficient between the object and the surface is 0.62. the resultant force of active earth pressure deviates from the normal direction - see figure: Distribution of earth pressure along structure for 0. Registration on or use of this site constitutes acceptance of our Privacy Policy. Ans: The coefficient of rolling friction of rubber on concrete ranges from 0.35 to 0.45. Spring Design Apps Note! The coefficient of sliding friction depends on what type of soil your retaining wall is sitting on. The strength of friction on wet surfaces is less compared to all other surfaces. P = gh ; where: P: Lateral pressure of concrete, kPa - : Concrete . This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework. The friction force can be calculated as Ff = 0.62 (100 lb) = 62 (lb) 1 lb = 0.4536 kg Example - Car, Braking, Friction Force and Required Distance to Stop A car with mass 2000 kg drives with speed 100 km/h on a wet road with friction coefficient 0.2. A washing machine pushed along with the floor. Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a parts function at the center of their design considerations. It is usually symbolized by the Greek letter mu (). Another commonly accepted way to determine the coefficient of friction is to substitute a soils internal angle of friction into the following equation: Some common values for the internal angle of friction of various soils include 30-40 (sand), 35 (gravel), 34 (silt) and, 20 (clay). What is a Truss? HVAC Systems Calcs The 1986 Specification states: The coefficient of friction shall be 0.90 for concrete placed against as-rolled steel with contact plane a full plate thickness below the concrete surface; 0.70 for concrete or grout placed against as-rolled steel with contact plane Date: 8/1/1999. Using Rankine's theory, Ka = 0.295 Active thrust from soil, Pal = jKvyh2 = { x . If you want to promote your products or services in the Engineering ToolBox - please use Google Adwords. Heat transfer coefficient ; The solver failed with a non-zero exit code of : 2 ; Getting graph and tabular data from result in workbench mechanical ; Difference between K-epsilon and K-omega Turbulence Model ; Time Step Size and Courant Number Can you explain this answer? If we consider one of the most common types of retaining walls, a Cantilever Retaining Wall, we must consider three major forces that will interact with one another to balance the sliding forces. Registration on or use of this site constitutes acceptance of our Privacy Policy. Internal friction angle 30o 4. Engineering Mathematics The friction force can be calculated as. The soil reinforcement designing by using geotextile requires the friction coefficient of soil-geotextile interface, both granular and cohesive soils. Thanks. Section Properties Apps Thank you for helping keep Eng-Tips Forums free from inappropriate posts.The Eng-Tips staff will check this out and take appropriate action. Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro .Add the Engineering ToolBox extension to your SketchUp from the SketchUp Pro Sketchup Extension Warehouse!
coefficient of friction between concrete and soil