00229833

Component

https://onlinepubs.trb.or...bproceedings/16/16-024.pdf

FOR DETERMINING THE PRESENCE AND LOCATION OF SOLID ROCK FOUNDATIONS, AND FOR CLASSIFYING SOILS AND OTHER UNDERLYING STRATA WITH REPECTS TO THEIR RELATIVE DEGREES OF COMPACTION, THE SEISMIC METHOD IS MORE DEPENDABLE THAN THE ELECTRICAL RESISTIVITY METHOD AND HAS AN INHERENT ADVANTAGE OVER ALL OTHER METHODS NOW USED, IN THAT IT MEASURES DIRECTLY THE RIGIDITY OF THE EARTH'S CRUST. A BLASTING CAP OR SMALL CHARGE OF DYNAMITE EXPLODED AT OR UNDER THE SURFACE OF THE GROUND BECOMES THE CENTER OF A WAVE DISTURBANCE. SENSITIVE MICROPHONE DETECTORS PLACED AT DIFFERENT DISTANCES FROM THE SHOT PICK UP THE DISTURBANCE SUCCESSIVELY AND TRANSMIT THE ELECTRIC IMPULSES TO GALVANOMETERS WHICH RECORD THEM AS LIGHT TRACES ON A MOVING PHOTOGRAPHIC FILM. BY MEANS OF AN ACCURATE TIMING MECHANISM THE TIME OF TRANSIT OF THE WAVE DISTURBANCE FROM THE SHOT POINT TO EACH DETECTOR IS ALSO INDICATED ON THE FILM, THE SPEED OF TRANSIT BEING INDICATIVE OF THE ELASTIC CHARACTER OF THE MATERIAL TRAVERSED. DATA FROM A NUMBER OF SHOTS ARE PLOTTED ON A TIME-DISTANCE CURVE, AND THE RELATIVE RIGIDITIES OF THE UNDERLYING MATERIALS THEREBY CLASSIFIED. THE THICKNESS OF SURFACE LAYERS OF SOFT MATERIAL OVER DENSER LAYERS OF CLAY OR SHALE ARE INDICATED, AND LIKEWISE THE DEPTH TO MATERIAL OF STILL GREATER RIGIDITY, SUCH AS SOLID ROCK. /AUTHOR/

Vol 16, pp 282-293, 12 FIG. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.

01490409

1937 (approximate)

Highway Research Board Proceedings

Digital/other

Foundations; Geophysics; Grading (Earthwork); Road construction; Rocks; Seismicity; Soil compaction; Soil types

Grading; Seismic investigations; Soil classification

Construction; Geotechnology; Highways

TRIS, TRB

Aug 15 1971 12:00AM

• AN EXPERIMENTAL STUDY OF BOND STRESS
• BOND OF VIBRATED CONCRETE
• CONCRETE SLABS REINFORCED WITH HIGH YIELD POINT STEEL BARS
• DESIGN AND OPERATION OF PLANTS FOR PRODUCING STABILIZED SOIL-BOUND ROAD MATERIAL
• DURABILITY TEST OF CERTAIN PORTLAND CEMENTS
• EARTH DAMS AND ROADS IN THE NATIONAL FORESTS
• EFFECT OF QUALITY OF CLAY ON SOIL MORTAR
• ESSENTIALS OF SOIL COMPACTION
• GASOLINE CONSUMPTION, TIRE WEAR AND COEFFICIENTS OF FRICTION ON VARIOUS ROAD SURFACES
• METHODS OF ESTIMATING HIGHWAY TRAFFIC VOLUME
• METHODS OF ESTIMATING VEHICULAR TRAFFIC VOLUME WITH THE AID OF TRAFFIC PATTERNS
• ORGANIZING FOR SAFETY
• PLACING, SPREADING, AND FINISHING STABILIZED ROAD MATERIALS
• PROGRESS REPORT ON BRICK ROAD EXPERIMENTS IN OHIO
• PULL-OUT TESTS FOR BOND RESISTANCE OF HIGH ELASTIC LIMIT STEEL BARS
• REPORT OF PROJECT COMMITTEE ON FILLERS AND CUSHION COURSES FOR BRICK AND BLOCK PAVEMENTS
• REPORT OF THE DEPARTMENT OF HIGHWAY FINANCE, A SUMMARY OF FINANCIAL SURVEYS IN NINE STATES
• REPORT OF THE DEPARTMENT OF SOILS INVESTIGATIONS
• REPORT OF THE JOINT COMMITTEE ON ROADSIDE DEVELOPEMENT OF THE AMERICAN ASSOCIATION OF STATE HIGHWAY OFFICIALS AND THE HIGHWAY RESEARCH BOARD
• RESULTS OF COOPERATIVE TESTS USING THE LOS ANGELES ABRASION MACHINE
• SAFE SIDE FRICTION FACTORS AND SUPERELEVATION DESIGN
• SNOW CONTROL BY TREE PLANTING
• SOIL STABILIZATION WITH COAL TAR
• STABILIZING SOILS WITH PORTLAND CEMENT, EXPERIMENTS BY SOUTH CAROLINA HIGHWAY DEPARTMENT AND DISCUSSION
• SURFACE-CHEMICAL FACTORS INFLUENCING THE ENGINEERING PROPERTIES OF SOILS
• THE FUNCTION OF WATER IN HARDENING CONCRETE
• THE PRESENT STATUS OF THE SULFATE CRYSTALLIZATION TEST FOR SOUNDNESS OF AGGREGATES
• THE RESULTS OF TESTS TO DETERMINE THE EXPANSIVE PROPERTIES OF SOILS
• THE TESTING AND USE OF ROAD TARS
• UNIFORM CLASSIFICATION OF HIGHWAY ACCOUNTS
• USE OF CUTBACKS AND ROAD OILS IN SOIL STABILIZATION