Full Load Test Research Articles

Evaluation of Aerodynamic Instability Mechanisms for Centrifugal Compressors—Part II: Advanced Analysis

The results of advanced analysis for labyrinth seal dynamic characteristics are compared to current methods of calculating aerodynamic excitation and to test rig data published in the literature to date. The results of a shop full load test are presented and compared to predicted stability parameters. Results of the labyrinth analysis of the full-load test compressor are presented. Conclusions and recommendations are given for high pressure compressor rotor dynamics analysis with design guidelines for evaluation of new or proposed compressor designs.

Micro-computer analysis of pile group settlement using independent point and shaft loads

A FORTRAN-77 micro-computer program to predict pile group settlements is presented. The program incorporates concepts described in a recent publication (J. M. Polo and J. L. M. Clemente, J. Geotech. Engng, ASCE, to appear), where the pile cap is considered rigid and point and shaft loads are treated independently. Pile settlements are considered to consist of three components: settlement of pile point due to point load, settlement of pile point due to shaft load and elastic shortening of the pile due to axial load. Each of these components is evaluated taking into account appropriate pile and soil deformation parameters and numerically generated settlement influence factors. Group settlements are evaluated by incorporating settlement interaction factors which are also numerically generated. The program design is such that it can be used with minimum effort. The few input parameters needed can be provided in a user friendly interactive environment. Program use is illustrated with the prediction of the load-settlement behavior of a full scale pile group load test reported in the literature. A typical program output is shown for this example. Results obtained are excellent, indicating the soundness of the previously proposed method when properly used. Results also show the adequacy of the present micro-computer program.

Full scale load test of granular piles with different densities and different proportions of gravel and sand on soft Bangkok clay. Technical note : Bergado, D T; Lam, F L Soils FoundV27, N1, March 1987, P86–93

Full scale load test of granular piles with different densities and different proportions of gravel and sand on soft Bangkok clay. Technical note : Bergado, D T; Lam, F L Soils FoundV27, N1, March 1987, P86–93

Full Scale Load Test of Granular Piles with Different Densities and Different Proportions of Gravel and Sand on Soft Bangkok Clay

The behavior of granular piles with different densities and different proportions of gravel and sand on soft Bangkok clay was investigated. A total of 13 piles were installed with 0. 30 m diameter and 8. 0 m long using a non-displacement cased borehole method with 1. 20 m spacing in a triangular pattern. The piles were grouped into 5 categories. Groups 1, 2, and 3 with 3 piles each, were constructed using sand compacted at 20, 15, and 10 hammer blows per layer, respectively. Group 4 was made of gravel mixed with sand in the proportion on 1:0. 30 by volume and group 5 was constructed with gravel; both groups consisted of two piles each were compacted at 15 blows per layer. Four active and 2 dummy piezometers were installed for monitoring pore pressures. The soil properties were investigated by the field vane and pressuremeter tests. The ultimate capacity of each granular pile was determined by using full scale plate load tests. Using the pressuremeter results and the method by Hughes et al (1975), the predicted ultimate pile capacity and load-settlement curve agreed well with the experimental data. The maximum bulge in the pile was observed to be about one pile diameter from the ground surface. It was found that the pile made of gravel with 15 blows per layer (Group 5) yielded the maximum ultimate pile capacity closely followed by the piles constructed out of sand with 20 blows per layer (Group 1). In an earlier investigation (Bergado et al, 1984), it was found that the ultimate pile bearing capacity was 3 to 4 times greater than that of the untreated ground and that the piles acted independently when the spacing was 3 pile diameters or greater.

Pile settlement in clay : McDonald, P; Moore, P J Proc 4th Australia-New Zealand conference on geomechanics, Perth, Western Australia, 14–18 May 1984 V2, P408–412. Publ Barton: Inst of Engineers, 1984

The settlement of single piles in clay is examined in relation to elastic solutions published by others. The critical parameter required for settlement analyses is the soil modulus. This parameter cannot be determined reliably by means of laboratory or field tests, other than full scale pile load tests from which an appropriate modulus can be back-calculated using elastic theory. A case study is presented in which the results of field and laboratory strength tests are evaluated and correlated with a modulus inferred from the measured pile settlements. An elastic finite element model is used to determine the influence of soil layering on settlements. It is shown that acceptable results may be obtained using an equivalent single modulus with published pile settlement solutions for homogeneous soil. (Author/TRRL)

Axial capacity of steel pipe piles in clay : Dennis, N D; Olson, R E Proc Conference on Geotechnical Practice in Offshore Engineering, Austin, Texas, 27–29 April 1983P370–388. Publ New York: ASCE, 1983

Development of theories for the prediction of the axial compressive and tensile load capacities of driven piles is made difficult by a variety of factors, e.g., disturbance of the soil and changes in the state of stress caused by pile driving, dragdown of soil from one layer into another, and pile/soil interaction during loading. In the absence of a well developed theory supported by field evidence, engineers have developed a series of empirical design rules utilizing coefficients which are evaluated using full scale pile load tests. The size of data bases used in these correlations has generally been small and the methods have been applied in cases where the supporting data have been inadequate. In the terrestrial environment it is generally possible to overcome uncertainties in design by driving piles to refusal or by using pile load tests to verify design assumptions. In the case of piles driven offshore, load tests are prohibitively expensive and the use of excessively conservative design assumptions may lead to installation problems. There is, therefore, a continuing need for improvement in design methods. The improvements are needed in the complementary areas of improving the fundamental theories and improving the supporting data base and empirical correlations. We have increased the size of the readily available data base, examined the accuracy of several existing design methods, and developed improved correlations which have led to a revised design procedure.

Construction of MIT-DOE 10-MVA superconducting generator

A 10-MVA synchronous alternator has been designed and constructed to demonstrate advanced concepts for power station generators with superconducting field windings in the rotor. The experimental generator is in the final stages of assembly in preparation for no load tests and a 30-day full load test. This paper describes the construction of the generator, including the details of the superconducting rotor with emphasis on the unusual features. Problems in fabrication and assembly are discussed.

Rock Sockets in Soft Rock

This paper describes the results of two full scale rock socket load tests conducted in conjunction with the foundation design of a sulfur dioxide removal plant located at the Four Corners Generating Station near Farmington, New Mexico. The tests were conducted in a soft shaley sandstone with an average unconfined compressive strength less than 1,500 psi (10.3×1033kPa). The strength parameters of the sandstone were investigated by means of laboratory triaxial shear tests as well as Menard pressure testing in the field. The sockets were loaded to a maximum of 2,000 kip (9.2×105kg) and were monitored by sets of Carlson strain gages along the length of the socket and along the bottom diameter. The results of these tests indicate the skin resistance mobilized to be nonuniform and that socket length greater than 2 diam or 3 diam do not significantly affect socket capacity.

Static Adaptive Algorithms for Computer Control of Diesel Engine Tests

Full load and partial load tests of a Diesel engine in a test bed have been studied. Algorithms for digital automatic control of both using a microcomputer are presented. These algorithms have been devised to be easily applicable to a great variety of engine and brake types. They are static adaptive, for they recognize the static characteristics of the system as it moves from one stable point to another, and use it to improve the following steps. Tests have been carried out on a Diesel test bed fitted with a 300 kW eddy-current brake. A Zilog-based microcomputer was used to implement the control. Results show good stability properties and quick convergence to the desired points.

Piles Subjected to Torsion

Analytical solutions are presented for the torsional response of piles embedded in elastic soil that is either homogeneous or where the stiffness is proportional to depth. The solutions are extended to more general variations of soil stiffness with depth and to cover behavior after peak shaft adhesion between pile and soil. Full scale torsion load tests are studied, and an analogy is suggested between the behavior of piles subjected to torsion loading and that of long compressible piles subjected to axial loading.

TRANSIENT ANALYSIS OF CAPACITOR MOTORS USING DYNAMIC PHASE COORDINATES THEORY

ABSTRACT This paper explains further development of phase co-ordinates theory as related to a specific type of single phase induction motors. Specific tests to find the parameters of the motor, and transient tests to verify the accuracy of the model carried out on the actual motor. The full-load run-up test results are satisfactorily compared with those obtained from the phase model analysis.

The Behavior of Piles Driven in Clay. II. Investigation of the Bearing Capacity Using Total and Effective Strength Parameters

This paper outlines research of large model piles and some full scale piles driven into insensitive clay to study the phenomenon of load transfer and the effect of pile driving on the soil. It is divided into two parts. Part I dealt with the stress field set up by driving a large model pile into an instrumented clay bed and the stresses measured for some full scale timber piles. Part II presents an evaluation of the load carrying capacity of the model pile and compares the results with full scale load tests. Soil properties are evaluated in terms of effective stress for an estimate of the bearing capacity of the piles.The short term bearing capacity of the pile shaft and base can be estimated by conventional methods based on the undrained shearing strength of the clay at the time of driving. However, after several load cycles and for long term bearing capacity, closer estimates are obtained by use of the effective skin friction and shearing strength parameters from drained tests. Previous bearing capacity theory can be used for estimating the ultimate base capacity and an approximate theory is presented to estimate the average effective radial stress on the pile shaft in connection with the ultimate shaft capacities. This proposed approach is supported by observations in some clays of low sensitivity, but requires further research in other types of clays.

Deep Excavations for the Manufacturers Life Centre, Toronto

Geotechnical considerations associated with deep excavations for the Manufacturers Life Centre in Toronto are discussed. The depth to shale bedrock and the necessity to obtain maximum access to the foundation grade resulted in selecting the use of tie backs into the overburden with or without rakers for supporting the soldier pile lagging system. Full scale load tests were carried out to prove the recommended geotechnical design parameters for the shoring system. Adhesion values obtained from full scale field tests on tie backs agreed closely with the shear strength obtained from laboratory quick triaxial tests. However a full scale loading test on an inclined raker footing gave a higher bearing value compared with conventional design procedures.

Full Scale Load Test of Prestressed Folded Plate Unit

First Name is required invalid characters Last Name is required invalid characters Email Address is required Invalid Email Address Invalid Email Address

Improving the Specifications for Power-Line Filters

The most important requirement of a power-line filter is its insertion loss under load. This paper discusses methods of extending and improving the technique of measuring insertion loss as specified in MIL-STD-220A. It discusses present equipment limitations in MIL-STD-220A that restricts full-load tests to frequencies above 100 kHz and limits maximum current to 100 amperes. However, it is realized that MIL-STD-220A is the only available specification at present. Therefore, the paper discusses methods of extending the MIL-STD-220A technique for measuring the insertion loss of filters for frequencies as low as 14 kHz and under loads as high as 200 amperes. A new buffer network that allows such measurements is described. In addition, a method is discussed for improving voltage regulation and reducing distortion of the power-line waveshape caused by power filters. These are two parameters which have been totally ignored when specifying power filters and which have been found to cause considerable electrical problems after installation.

2226 東京海上ビル旧館の振動および破壊実験 : (その6)鉄筋コンクリート小梁付き実在スラブの破壊実験NO.2(構造)

2226 東京海上ビル旧館の振動および破壊実験 : (その6)鉄筋コンクリート小梁付き実在スラブの破壊実験NO.2(構造)

Methods of measuring arc-drop voltage on mercury-arc rectifiers

THE over-all efficiency of a mercury-arc rectifier unit is determined by the segregated loss method. The losses in the component parts of the unit ? the rectifier transformer, rectifier, and its auxiliaries ? are measured separately, and the efficiency is calculated. The methods used for measuring the losses are specified in the American Standards Association (ASA) Standard for Pool Cathode Mercury-Arc Power Converters.1 This method is used for determining the efficiency, instead of measuring the power input and output of the unit, for two reasons: 1. The losses constitute a relatively small percentage of the unit rating (approximately 5 per cent for a d-c output voltage of 600 volts) and can be determined more accurately by individual loss measiuements. 2. To set up a complete rectifier unit in the factory for a full-load test would be costly and is not always pcactical, because of the limitations of available testing facilities.

Notes on the testing of static transformers

The paper describes the usual methods adopted in the commercial testing of static transformers. Emphasis is laid on the need for accuracy, and methods are suggested whereby it can be obtained.The drying-out of transformers, the determination of dryness, and the measurement of insulation resistance are discussed. The measurement of the iron loss and load loss is described, together with methods for obtaining greater accuracy.The measurement of form factor and its effect on the less measurements are dealt with; and methods for determining the ohmic resistance, also corrections for the same, are detailed.The loading of transformers for a full-load test, and the temperature-rise readings obtained on this test, are discussed. Over-potential and pressure testing are described, and the methods of measuring high voltages are detailed.