SUMMARIZATION AND COMPARISON OF ENGINEERING PROPERTIES OF LOESS IN THE UNITED STATES

DATA WERE GATHERED ON ENGINEERING PROPERTIES OF LOESS IN THE UNITED STATES. LOESS MAY BE IDENTIFIED PRIMARILY BY ITS COLOR AND PARTICLE SIZE. LOESS IS COMPOSED PRIMARILY OF RATHER LOSELY ARRANGED ANGULAR GRAINS OF SAND, SILT, AND CLAY. SILT IS USUALLY THE DOMINANT SIZE. CALCITE IS ALSO GENERALLY PRESENT IN AMOUNTS RANGING FROM ZERO TO MORE THAN 10% OF THE TOTAL SOIL. THE FOLLOWING PROPERTIES ARE DISCUSSED AND ANALYZED: SPECIFIC GRAVITY, ATTERBERG LIMITS, PERMEABILITY, DENSITY, SHEAR STRENGTH, CONSOLIDATION, BEARING CAPACITY, NATURAL MOISTURE CONTENT AND EROSION. IT IS CONCLUDED THAT LOESS IS A SOIL PREDOMINATELY SILT-SIZE WITH SMALL AMOUNTS OF SAND. THE PHYSICAL CHARACTERISTICS OF GRADATION, COMPACTION, ATTERBERG LIMITS, AND CLASSIFICATION ARE VERY UNIFORM. THE STRUCTURE IS OPEN AND POROUS AND BONDING IS PRIMARILY DUE TO THIN CLAY COATINGS. IN-PLACE DENSITIES RANGE FROM 66 TO 104 PCF. LARGE SETTLEMENTS ARE UNCOMMON FOR IN-PLACE DENSITIES OF OVER 90 PCF. NATURAL MOISTURE CONTENTS ARE GENERALLY WELL BELOW SATURATION AND RANGE FROM 4 TO 49 PERCENT. BEARING CAPACITY DEPENDS PRIMARILY ON THE IN-PLACE DENSITY. CONSOLIDATION PROCEEDS RAPIDLY UNDER LOAD WHEN LOESS IS SATURATED OR NEAR SATURATION. SHEARING STRENGTH IS GREATLY DEPENDENT ON MOISTURE CONTENT.