MEASUREMENTS OF LATERAL EARTH PRESSURE IN DRILLED SHAFTS

THIS PROJECT INVOLVES THE DESIGN, CONSTRUCTION, AND TESTING, IN THE LABORATORY AND FIELD, OF INSTRUMENTATION CAPABLE OF MEASURING THE LATERAL EARTH PRESSURES ALONG A DRILLED SHAFT. THIS PROJECT SUMMARIZES AND SYNTHESIZES THE THEORIES WHICH SET THE DESIGN CRITERIA FOR SOIL PRESSURE MEASURING DEVICES BASED ON SOIL BEHAVIOR. THE PROJECT ASSIMILATES THE PRESENT KNOWLEDGE CONCERNING TRANSDUCERS AND PRODUCES A PRESSURE CELL DESIGNED TO MEASURE LATERAL PRESSURES AGAINST A DRILLED SHAFT UP TO 50 PSI. DESIGN 'MAPS' BASED ON TIMOSHENKO'S THEORY OF A CLAMPED EDGE, CIRCULAR, THIN PLATE ARE GIVEN. THESE 'MAPS' ALLOW THE INVESTIGATOR TO ARRIVE AT THE THICKNESS OF A DIAPHRAGM KNOWING THE DESIRED PRESSURE TO BE MEASURED, THE DIAPHRAGM DEFLECTION TO DIAMETER RATIO, AND THE DESIRED SENSITIVITY OF THE CELL. A BERYLLIUM COPPER CELL 2 3/4 INCHES IN DIAMETER AND 1/2 INCH THICK WAS CONSTRUCTED. THE ELECTRONIC PRESSURE SENSING ELEMENT IS A SPECIAL FOUR-ARM BONDED FOIL STRAIN GAGE. THE CELL HAS BEEN USED TO MEASURE THE PRESSURES EXERTED AGAINST A DRILLED SHAFT UNDER CURING AND LOADING CONDITIONS. ADDITIONAL WORK WILL BE NEEDED TO EVALUATE COMPLETELY THE LATERAL-EARTH-PRESSURE DISTRIBUTION AND LOAD TRANSFER FROM SHAFT TO SOIL. IT IS FELT THAT THE DESIGNED GAGE IS SATISFACTORY. /AUTHOR/

[1]  B F McCullough,et al.  A STATEWIDE DEFLECTION STUDY OF CONTINUOUSLY REINFORCED CONCRETE PAVEMENT IN TEXAS , 1966 .

[2]  G. S. Jain,et al.  Load-Bearing Capacity of Piles , 1963 .

[3]  F N Hveem,et al.  DEVICES FOR RECORDING AND EVALUATING PAVEMENT ROUGHNESS , 1960 .

[4]  W H Cogill.  ANALYTICAL METHODS APPLIED TO THE MEASUREMENTS OF DEFLECTIONS AND WAVE VELOCITIES ON HIGHWAY PAVEMENTS: PART 2, MEASUREMENTS OF WAVE VELOCITIES , 1969 .

[5]  Thurmul Francis McMahon.  Design of a Pressure Sensitive Cell and Model Studies of Pressures in the Subgrade of a Flexible Pavement System , 1959 .

[6]  F H Scrivner,et al.  A SYSTEMS APPROACH APPLIED TO PAVEMENT DESIGN AND RESEARCH , 1970 .

[7]  C. Hodgman.  Mathematical tables : from handbook of chemistry and physics , 1954 .

[8]  F H Scrivner,et al.  An electro-mechanical system for measuring the dynamic deflection of a road surface caused by an oscillating load , 1964 .

[9]  K. Terzaghi,et al.  Soil mechanics in engineering practice , 1948 .

[10]  E. Selig,et al.  Instruments and apparatus for soil and rock mechanics , 1965 .

[11]  R. Cooke,et al.  Experiments on Model Piles with Enlarged Bases , 1961 .

[12]  G. G. Meyerhof,et al.  An investigation of the Bearing Capacity of Some Bored and Driven Piles in London Clay , 1953 .

[13]  G L Dehlen.  A SIMPLE INSTRUMENT FOR MEASURING THE CURVATURE INDUCED IN A ROAD SURFACING BY A WHEEL LOAD , 1962 .

[14]  B F McCullough,et al.  DETERMINING THE RELATIONSHIP OF VARIABLES IN DEFLECTION OF CONTINUOUSLY-REINFORCED CONCRETE PAVEMENT , 1966 .

[15]  L Bjerrum,et al.  MEASURING INSTRUMENTS FOR STRUTTED EXCAVATIONS , 1965 .

[16]  R. W. Sparrow,et al.  The fundamental action of earth pressure cells , 1954 .

[17]  Frank H Scrivner,et al.  Some Recent Findings In Flexible Pavement Research , 1967 .

[18]  James L. Brown,et al.  A RECOMMENDED TEXAS HIGHWAY DEPARTMENT PAVEMENT DESIGN SYSTEM USER'S MANUAL , 1970 .

[19]  S. Chandra,et al.  Frictional Resistance of Bored Piles in Expansive Clays , 1961 .

[20]  G L Dehlen.  FLEXURE OF A ROAD SURFACING, ITS RELATION TO FATIGUE CRACKING, AND FACTORS DETERMINING ITS SEVERITY , 1962 .

[21]  L A Dubose.  SMALL-SCALE LOAD TESTS ON DRILLED AND CAST-IN-PLACE CONCRETE PILES , 1957 .

[22]  F H Scrivner,et al.  A TENTATIVE FLEXIBLE PAVEMENT DESIGN FORMULA AND ITS RESEARCH BACKGROUND , 1966 .

[23]  F H Scrivner,et al.  A SYSTEMS APPROACH TO THE FLEXIBLE PAVEMENT DESIGN PROBLEM , 1968 .

[24]  Hudson Matlock,et al.  DISCONTINUOUS ORTHOTROPIC PLATES AND PAVEMENT SLABS , 1965 .

[25]  H. Bolton Seed,et al.  Closure of "The Action of Soft Clay along Friction Piles" , 1957 .

[26]  Lymon C. Reese,et al.  Load Transfer for Axially Loaded Piles in Clay , 1966 .

[27]  Investigations of soil pressure measuring by means of cells , 1956 .

[28]  Alec Westley Skempton,et al.  Cast In-Situ Bored Piles in London Clay , 1959 .