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Nondestructive evaluation of existing deep foundations
282A
SURFACE STRUCTURES:FOUNDATIONS
Foundations
956239 Finite element analysis of cutting resistance in foundation desigo Z. Czap, Periodica Polytechnica: Civil Engineering, 38(l), 1994, pp 21-28. Cutting resistance values suggested by Jaky sad Kexdi for detennining load capabilities of spread aad deep footings have beea compared to computer outputs. In conformity with analytic and numerical analysis results, FEM is suggested for compiling tables or diagrmns for designing concrete strip and pier footings. The required material characteristics of coacrete are defined sad the possible procedure of computations outlined. (Author)
956240 A new fuodamental solution for boundary element analysis of tbio plate on Winkler foundation A. El-Zafraay, S. Fadhil & K. Al-Hosani, International Journal for Numerical Methodr in Engineering, 38(6), 1995, pp 887-903. This paper introduces aa efficient boundary element approach for the analysis of thin plates, with arbitrary shapes sad bouadary conditions, resting on an elastic Wiakler foundation. Boundary integral equations with three degreesof-freedom per node are derived without unknown comer terms. A fundamental solution based upon newly defined modified Kelvin functions is formulated and it leads to a simple solution to the problem of divergent integrals. Reduction of domain loading terms for cases of distributed and concentrated loading is also provided. Case studies, including plates with free-edge conditions, are demonstrated. (from Authors)
956241 Nondestructive evaluation of existing deep foundatioos A. G. Davis, Journal of Performance of Constructed Facilities - AXE, 9(l), 1995, pp 57-74. It is not always realixed that the performance evaluation of older, deep foundations under existing structures can be enhanced by nondestructive testing. The NDT techniques currently available for this objective are described and critically reviewed in this paper. Case histories illustrating the use of different methods to iaspect existing piles, drilled shafts, and caissons are presented. (Author)
956242 Foundatioo of a 157 m high transmission tower J. Farkas & L. Marcxal, Periodica Polytechnica: Engineering, 38(l), 1994, pp 29-40.
Civil
In a city of Hungary known to have a weak subsoil, a microwave transarissioa tower 157 m high, with a cylindrical reinforced concrete shaft was built. In its design, possibilities of both spread foundation aad deep foundation arose. Beyond dead and live loads, other effects (wind load, seismic effects, uniform sad nonuniform settlement, daily aad seasonal temperature variations) had to be reckoned with. In case of spread footing, that should be 25-30 m diameter because of the extreme height, uneven settlement and tilting, rather than soil failure, were the main problems. The tower was eventually built on spread foundation. During and after coastructioa, stresses under the slab footing were recorded sad horixoatal aad vertical displaceme ats of the tower observed. (from Authors)
956243 Determination of loads 00 caotilevers of ecceotrically loaded formdation slabs E. V. Neiburg, Soil Mechanics & Founabion Engineering, 31(4), 1994(1995), pp 137-140; translated from: Omovaniya, Funabmenty i Mekhanika Gruntov, 4, 1994, pp 14-16.. Fonaulas for determining loads on cantilevers of eccentrically loaded foundations were obtained for the example of strip foundations. Cases of symmetric and asymmetric arrangemeat of the slabs relative to the wall blocks resting on these slabs are examin ed. A method is proposed for selecting slabs on the basis of bearing capacity. (Journal summary) 956244 Etude experimeotale du cbargement lateral cyciique repete des pieux isoles dans le sable en centrifugeuse (Experimental study of repetitive cyclic lateral loading oo sand piles using a centrifuge) AoB;u8aBa, Canadian Geotechnical Journal, 31(5), 1994, pp . This paper presents the results of repetitive cyclic lateral loading test carried out in a centrifuge on two reduced models of single piles instrumented with strain gauges. The pile models, their instnaneatatioa, the experimental setup, aad the construction of the soil model are described. Effects of the pile surface roughness and of sand density on the pile behaviour are studied. Finally, the paper deals with the construction of P-Y lateral reaction curves sad the variation of the horizontal subgrade modulus with the number of cycles. (English summary) 956245 Approximate elastic-plastic solution for axially loaded piles E. Motta, Journal of Geotechnical Engineering - ASCE, 120(9), 1994, pp 1616-1624. Aa approximate elastic perfectly plastic solutioa in a closed forar for axially loaded piles based on the t-z curve method, is presented. The closed-fona solutioa allows prediction in a very simple way of vertical pile movements sad settlement at the pile head as well as the value of the sxial load at a certain depth from the ground surface. Diifereat from elastic solutions, the method can take into account the nonlinear behavior of the load-settlement curve. The method does not apply to situations where a sigaificaat portion of the working load is derived from end-bearing capacity. (from Author) 956246 Use of static probing to determine tbe resistance of piles of circular cross section witb an open lower end G. V. Mitkiaa, Soil Mechanics & Foumkztion Engineering, 31(4), 1994(1995), pp 128-133; translated from: Omovaniya, Funabmenty i Mekhanika Gruntov, (4), 1994, pp 6-10. A method of evaluatiag the vertical-loadiag resistance of circular piles with aa open end from the results of static probing is cited. Limiting pile resistances, as determined by testing, are compared with coetBcieats proposed by the author. The progrma ‘KOL’TsO’, which automates circulation of the bearing capacity of a circular pile from staticprobe data, is developed. (Journal summary) 956247 Touchdown for O-cell teat B. J. Meyer & P. R. Schade, Civil Engineering - ASCE, 65(2), 1995, pp 57-59. The Los Angeles Memorial Coliseum was badly damaged by the Northridge earthquake. Sevea months were allocated to complete 3 years of work. The project fell behind schedule immediately. It took three weeks to install the first two 95foot-long piles. Severe caving soil conditions and craraped
SURFACE STRUCTURES:FOUNDATIONS
Foundations
956239 Finite element analysis of cutting resistance in foundation desigo Z. Czap, Periodica Polytechnica: Civil Engineering, 38(l), 1994, pp 21-28. Cutting resistance values suggested by Jaky sad Kexdi for detennining load capabilities of spread aad deep footings have beea compared to computer outputs. In conformity with analytic and numerical analysis results, FEM is suggested for compiling tables or diagrmns for designing concrete strip and pier footings. The required material characteristics of coacrete are defined sad the possible procedure of computations outlined. (Author)
956240 A new fuodamental solution for boundary element analysis of tbio plate on Winkler foundation A. El-Zafraay, S. Fadhil & K. Al-Hosani, International Journal for Numerical Methodr in Engineering, 38(6), 1995, pp 887-903. This paper introduces aa efficient boundary element approach for the analysis of thin plates, with arbitrary shapes sad bouadary conditions, resting on an elastic Wiakler foundation. Boundary integral equations with three degreesof-freedom per node are derived without unknown comer terms. A fundamental solution based upon newly defined modified Kelvin functions is formulated and it leads to a simple solution to the problem of divergent integrals. Reduction of domain loading terms for cases of distributed and concentrated loading is also provided. Case studies, including plates with free-edge conditions, are demonstrated. (from Authors)
956241 Nondestructive evaluation of existing deep foundatioos A. G. Davis, Journal of Performance of Constructed Facilities - AXE, 9(l), 1995, pp 57-74. It is not always realixed that the performance evaluation of older, deep foundations under existing structures can be enhanced by nondestructive testing. The NDT techniques currently available for this objective are described and critically reviewed in this paper. Case histories illustrating the use of different methods to iaspect existing piles, drilled shafts, and caissons are presented. (Author)
956242 Foundatioo of a 157 m high transmission tower J. Farkas & L. Marcxal, Periodica Polytechnica: Engineering, 38(l), 1994, pp 29-40.
Civil
In a city of Hungary known to have a weak subsoil, a microwave transarissioa tower 157 m high, with a cylindrical reinforced concrete shaft was built. In its design, possibilities of both spread foundation aad deep foundation arose. Beyond dead and live loads, other effects (wind load, seismic effects, uniform sad nonuniform settlement, daily aad seasonal temperature variations) had to be reckoned with. In case of spread footing, that should be 25-30 m diameter because of the extreme height, uneven settlement and tilting, rather than soil failure, were the main problems. The tower was eventually built on spread foundation. During and after coastructioa, stresses under the slab footing were recorded sad horixoatal aad vertical displaceme ats of the tower observed. (from Authors)
956243 Determination of loads 00 caotilevers of ecceotrically loaded formdation slabs E. V. Neiburg, Soil Mechanics & Founabion Engineering, 31(4), 1994(1995), pp 137-140; translated from: Omovaniya, Funabmenty i Mekhanika Gruntov, 4, 1994, pp 14-16.. Fonaulas for determining loads on cantilevers of eccentrically loaded foundations were obtained for the example of strip foundations. Cases of symmetric and asymmetric arrangemeat of the slabs relative to the wall blocks resting on these slabs are examin ed. A method is proposed for selecting slabs on the basis of bearing capacity. (Journal summary) 956244 Etude experimeotale du cbargement lateral cyciique repete des pieux isoles dans le sable en centrifugeuse (Experimental study of repetitive cyclic lateral loading oo sand piles using a centrifuge) AoB;u8aBa, Canadian Geotechnical Journal, 31(5), 1994, pp . This paper presents the results of repetitive cyclic lateral loading test carried out in a centrifuge on two reduced models of single piles instrumented with strain gauges. The pile models, their instnaneatatioa, the experimental setup, aad the construction of the soil model are described. Effects of the pile surface roughness and of sand density on the pile behaviour are studied. Finally, the paper deals with the construction of P-Y lateral reaction curves sad the variation of the horizontal subgrade modulus with the number of cycles. (English summary) 956245 Approximate elastic-plastic solution for axially loaded piles E. Motta, Journal of Geotechnical Engineering - ASCE, 120(9), 1994, pp 1616-1624. Aa approximate elastic perfectly plastic solutioa in a closed forar for axially loaded piles based on the t-z curve method, is presented. The closed-fona solutioa allows prediction in a very simple way of vertical pile movements sad settlement at the pile head as well as the value of the sxial load at a certain depth from the ground surface. Diifereat from elastic solutions, the method can take into account the nonlinear behavior of the load-settlement curve. The method does not apply to situations where a sigaificaat portion of the working load is derived from end-bearing capacity. (from Author) 956246 Use of static probing to determine tbe resistance of piles of circular cross section witb an open lower end G. V. Mitkiaa, Soil Mechanics & Foumkztion Engineering, 31(4), 1994(1995), pp 128-133; translated from: Omovaniya, Funabmenty i Mekhanika Gruntov, (4), 1994, pp 6-10. A method of evaluatiag the vertical-loadiag resistance of circular piles with aa open end from the results of static probing is cited. Limiting pile resistances, as determined by testing, are compared with coetBcieats proposed by the author. The progrma ‘KOL’TsO’, which automates circulation of the bearing capacity of a circular pile from staticprobe data, is developed. (Journal summary) 956247 Touchdown for O-cell teat B. J. Meyer & P. R. Schade, Civil Engineering - ASCE, 65(2), 1995, pp 57-59. The Los Angeles Memorial Coliseum was badly damaged by the Northridge earthquake. Sevea months were allocated to complete 3 years of work. The project fell behind schedule immediately. It took three weeks to install the first two 95foot-long piles. Severe caving soil conditions and craraped