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Team Assignments. A Clayten Greenwell Elliot Magoto Jonathan Morgan Lisa Woosley B Joshua Cecil Zachary Rabold Richard Smith Robert Talley C Ryan Franklin Anthony Stegman Zachary Stucker Joshua Von Schlutter D Christian Pendleton Nathan Piersma Matthew Rogers
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Team Assignments • A • Clayten Greenwell • Elliot Magoto • Jonathan Morgan • Lisa Woosley • B • Joshua Cecil • Zachary Rabold • Richard Smith • Robert Talley • C • Ryan Franklin • Anthony Stegman • Zachary Stucker • Joshua Von Schlutter • D • Christian Pendleton • Nathan Piersma • Matthew Rogers • Hayden Smith
Team Assignments • E • Christopher Collins • Mark Lacy • Adam Leach • Daniel Rehner • F • Cory Boughey • Matthew Broaddus • Cory Henon • Stephen Howell • G • Christopher Allison • Brett Blanchard • Travis Greenwell • Samantha Thomas
CE403 Construction Methodology Earthwork Fundamentals
LEARNING OBJECTIVES • Define the common Soil Properties and how to determine each. • Define Soil-Volume Changes that occur during earthmoving operations. • Define Swell, and Shrinkage, and how to determine the Load & Shrinkage Factors. • Define Angle of Repose for common Soil Materials. • Describe the two common Soil Classification Systems and Basic Definitions.
Soil Properties • Any mass of soil consists of solid particles with voids in between. • Soil solids are small grains of different minerals • Voids can be filled with either water or air
Soil Properties • Total volume of the soil mass, Vt, consists of volume of soil solids, Vs, and the volume of voids, Vv • The volume of the Voids, Vv, consists of volume of water, Vw, and the volume of air, Va
Soil Properties • We can schematically represent these three phases in a phase diagram. Volume Mass
Soil Properties • Three volumetric ratios • Void ratio: • Normally expressed as a decimal • Max range of e is between 0 and infinity • Typical values: Sand (0.4 to 1.0); Clays (0.3 to 1.5)
Soil Properties • Three volumetric ratios • Porosity • Normally expressed as a decimal • Max range of n is between 0 and 100%
Soil Properties • Three volumetric ratios • Degree of Saturation • The degree of saturation tells us what percentage of the total volume of voids contains water • If soil is completely dry, S=0. If the pores are completely filled with water, S=100%
Soil Properties • Mass relationships • Water (moisture) content: • Can range from zero (dry soil) to several hundred percent • Water content for most soils is well under 100%, although it can range up to 500% or higher in some marine and organic soils
Soil Properties • Mass relationships • Total density: • Magnitude will depend on amount of water in the voids and density of the mineral grains • Typical values for most soils range from 1000 to 2400 kg/m3
Soil Properties • Mass relationships • Solid density: • Typical values for most soils range from 2500 to 2800 kg/m3 (2.65 Mg/m3) • Dry Density:
Soil Properties • Mass relationships • Density of Water: • The density of water varies slightly, depending on the temperature. • For most engineering work, it is sufficiently accurate to estimate pw=1000kg/m3=62.4lb/ft3
Example Problem Given the Following: Vs=65 cm3, Vw=25 cm3, Va=10cm3 Ms = 175g, Mw=25g Find: Total Density, dry density, moisture content, void ratio, saturation, and porosity of the soil sample
Soil Volume-Change Characteristics Bank Volume - (BCY) • Material is in natural state before disturbance Loose Volume - (LCY) • Material has been excavated or loaded. Compacted Volume - (CCY) • Material after compaction.
Swell • A soil increases in volume when it is excavated because the soil grains are loosened during excavation and air fills the void spaces created.
Shrinkage • When soil is compacted, air is forced out of void spaces. • The soil will occupy less volume than it did under either bank or loose conditions.
Load & Shrinkage Example Problem A soil weighs 1,960 lb/LCY, 2,800 lb/BCY and 3,500 lb/CCY. b. How many BCY & CCY are contained in 1,000,000 LCY? Bank Volume 1,000,000 LCY x 1,960/2,800(BCY/LCY) = = 1,000,000 LCY x 0.70(BCY/LCY) = 700,000 BCY Compacted Volume 1,000,000 LCY x 1,960/3,500 (CCY/LCY)= or = 700,000 BCY x 0.80 (CCY/BCY) = 560,000 CCY
Unified Soil Classification System • Two Letter System • Symbols to represent soil type: Symbol Soil Type G Gravel S Sand M Silt C Clay Pt Highly organic soil and peat. • Symbols to represent index properties W Well-graded (for grain-size distribution) P Poorly-graded (for grain-size distribution) L Low to medium plasticity H High plasticity
Angle of Repose • The angle that the sides of a spoil bank or pile naturally form with the horizontal when the excavated soil is dumped onto a pile. • The angle varies with the soil’s physical characteristics and its moisture content.
Materials & Angle of Repose Clay 35° Common Earth, Dry 32° Common Earth, Moist 37° Gravel 35° Sand, Dry 25° Sand, Moist 37°
H D Spoil Pile Dumped from a single fixed point Volume =1/3 Base Area x Height
Basic Definitions • The liquid limit (LL) is the water content (%) at which the soil will just start to flow when subjected to standard shaking test. (Casagrande Test) • The plastic limit is the moisture content (%) at which the soil just begins to crumble when rolled into a thread 1/4” in diameter. • The plastic index is the numerical difference between the liquid and plastic limits and represents the range in moisture content over which the soil remains plastic.
Unified Soil Classification System • Two Letter System • Symbols to represent soil type: Symbol Soil Type G Gravel S Sand M Silt C Clay Pt Highly organic soil and peat. • Symbols to represent index properties W Well-graded (for grain-size distribution) P Poorly-graded (for grain-size distribution) L Low to medium plasticity H High plasticity
AASHTO Soil Classification System • American Association of State Highway and Transportation Officials • A-1 through A-7 • Table 2-3, Page 25.
Construction Characteristics of Soils • Drainage • Construction Workability • Suitability for Subgrade • Suitability for Surfacing