Full-scale field tests on directly embedded steel pole foundations

2000 ◽  
Vol 37 (2) ◽  
pp. 414-437 ◽  
Author(s):  
Asim Haldar ◽  
VSN Prasad Yenumula ◽  
T R Chari

The results of eight full-scale tests on directly embedded steel pole foundations are presented. Fully instrumented poles were tested to measure the various design parameters. Different types of backfills such as sand, in situ gravelly sand, crushed stone, and flowable material were used. Various parameters were measured, including applied moment, ground line deflection-rotation, rotation of the pole below the ground level, soil pressures, and bending moments in the poles. The behaviour of these foundations was explained through ultimate capacity and moment-rotation characteristics. Based on these test results, it was found that the capacity of the directly embedded pole foundation depends primarily on the compaction levels of backfill and the embedment length of the pole. Flowable backfill material, which does not require any compaction, was found to be most effective and promising. Even when the backfill was loose, the lateral capacity significantly increased by the addition of a baseplate or by installing the pole with an additional embedment depth. Various theories developed for laterally loaded rigid piles were used to predict the moment-rotation behaviour and the ultimate capacity of the directly embedded pole foundation with different types of backfill material. Results from the analytical investigations were compared with those obtained from the full-scale load tests. Comparisons show that the ultimate capacities predicted by the models ranged from 0.30 to 2.20 times the measured capacities.Key words: backfill, compaction, full-scale tests, laterally loaded rigid piles, transmission steel poles, ultimate moment.

Author(s):  
Yu. I. Buryak ◽  
A. A. Skrynnikov

The article is devoted to the substantiation of the procedure for testing complex technical systems to assess the probability of performing the task, taking into account a priori data obtained from the results of modeling, field tests of components and prototypes, operation of analogues, etc. The conditions for the formation of a combined sample consisting of field experiments and experiments counted on the results of modeling are justified. Data uniformity is checked using the Student's criterion. The minimum volume of full-scale tests is determined by the requirement of equality of the amount of Fischer information about the estimated parameter obtained during full-scale tests and at the expense of a priori data A strategy for conducting field experiments is proposed, in which the required quality of evaluating the probability of completing the task is achieved with the minimum possible number of field experiments. At the first stage, a series of experiments with a volume equal to half of the required sample size is performed. At the second stage, the experiments are conducted sequentially with an assessment after each experiment of the requirements for the amount of information about the evaluated parameter and for the uniformity of data. Experiments are terminated when the specified requirements are met, and then a combined sample is formed, which is used to evaluate the probability of the system performing the task. A model example is considered. The estimation of the gain in the number of experiments performed at different probability values was carried out.


2021 ◽  
Vol 2021 (10) ◽  
pp. 45-52
Author(s):  
Denis D'yakov ◽  
Iskander Valiulin ◽  
Dmitriy Lihovidov ◽  
Aleksey Velikanov

The purpose of the research in this paper is to develop a promising airfield driverless tow truck to increase the economic efficiency of aircraft towing facilities, including unmanned aircrafts as well as to ensure reliable operation in various climatic conditions. The research methods include the analysis of the experience of using such driverless airfield tow trucks abroad, the theory of calculating traction and speed indicators and experimental studies conducted during the creation and study of field tests of devices used to load the driving wheels of a tractor. To achieve the goal, the configuration of the structure being designed and its intended composition are determined analytically. The operation of the designed device in the traction mode is considered, and the characteristic of calculating its indicators when moving along the support surface is presented. The presented material briefly illustrates the process from creating a model of a driverless airfield tow truck to the created design of an existing sample, which will later be used to conduct its full-scale tests and a comprehensive assessment of its strength traction and speed characteristics.


2020 ◽  
Vol 212 ◽  
pp. 02015
Author(s):  
Mikalai Shalabyta ◽  
Andrei Shuryn ◽  
Tatsiana Shalabyta ◽  
Viacheslav Dragan

There are quite often statically complex structures, the reliability of theoretical calculations of which needs experimental verification in the world practice of design and construction. Studies of building structures functioning can be full-scale or carried out on their models in laboratory conditions depending on the goals set. Full-scale tests of building structures are more expensive, therefore, their implementation requires a special approach and justification. However, to check the operation of complex, critical structures which primarily include metal spatial large-span structures of coatings of buildings and structures especially those used for the first time to assess their bearing capacity, to establish the degree of participation in the construction of each of the elements, to study the operation of individual new nodal elements etc., only full-scale tests are required.


2021 ◽  
Vol 26 (1) ◽  

Full-scale tests are widely used to reliably evaluation the service life of paint and varnish coatings by assessing changes of their protective and decorative properties. Four-year exposure program was carried out in the tropical marine climate in South Vietnam (Dam Bay climate station of the Tre island, Nha Trang) of alkyd, chlorinated rubber coatings on low carbon steel, as well as epoxy coatings of various thicknesses with zinc-rich primer, urethane and acrylic outer layers. The tests were conducted on the base of the existing standards in the field of paints and varnishes intended for coastal and ship structures and were accompanied by the data collection and analysis of the meteorological factors for the classification of the area according to the degree of corrosiveness of the atmosphere. The change in the decorative properties of paint coating was assessed by visual and instrumental methods. The protective efficiency of the coatings was assessed by the time of occurrence of the first local defects or complete destruction of coating layers. According to the results of the conducted field tests, it was found that paint coating combinations correspond to expected lifetime in tropical climate from 2 to 5 years. A typical group suitable for a given climate is a two-component epoxy paint with an acrylic topcoat. A zinc-containing primer is recommended as an anticorrosive undercoat.


1996 ◽  
Vol 23 (2) ◽  
pp. 536-548 ◽  
Author(s):  
C. E. Ventura ◽  
A. J. Felber ◽  
S. F. Stiemer

This paper presents the results of full-scale tests performed at the Colquitz River Bridge near Victoria, British Columbia (B.C.), Canada, during September 1992 to determine the dynamic characteristics of the structure. The five-span bridge was completed in 1954 and is part of the Trans-Canada Highway. It is 82.68 m long and 11.89 m wide, and has six continuous steel girders supporting a 175 mm thick concrete deck. This particular bridge was chosen for testing because of its typical nature of many B.C. bridges, its location in an area of high seismic risk, and its excellent site accessibility. The tests included extensive measurements of ambient vibrations induced by traffic and other sources to determine the dynamic characteristics of the bridge. The most significant vertical and lateral mode shapes and associated periods of vibration were determined from vibration measurements at more than 50 different locations of the deck, piers, and abutments. Although a large amount of data were collected, they were quickly processed and analyzed with an innovative system developed at The University of British Columbia. One of the important features of this system is that it permits the identification of the principal modes of vibration immediately after the data have been collected. In addition to the ambient vibration tests, quick release pullback tests were conducted to verify modal frequencies determined from the ambient vibration tests and to determine the damping of the fundamental modes. These tests consisted of loading the bridge at a selected location with a force of about 90 kN and then releasing this load very quickly to induce free vibrations. The information obtained from the field tests was used to refine a computer finite element model of the bridge, which, in turn, was used to gain insight into the dynamic behaviour of specific components of the bridge. Further, this information was used later by the bridge owner to evaluate the bridge's expected response during an earthquake. Key words: steel bridges, dynamic response, full-scale tests.


Géotechnique ◽  
2021 ◽  
pp. 1-31
Author(s):  
David J. Richards ◽  
William Powrie ◽  
Anthony P. Blake

Author(s):  
George Karabelas ◽  
Geoff Redfern ◽  
Brad Jacobs ◽  
Andrew Roberts ◽  
Upul Fernando ◽  
...  

One riser and two flowline sections installed in the Suncor Energy Terra Nova riser replacement programme were shown to leak during field tests performed after site installation. No hydrocarbon loss occurred nor was there an environmental incident; however, the scheduled production start-up for the pipes was delayed. The pipes were designed and manufactured to comply with API [1] code and had successfully undergone full-scale factory acceptance testing (FAT) at 1.5 times design pressure following manufacture. Investigations confirmed that the leaks in both pipes occurred due to a crack in the polymer (PVDF) barrier within the end-fitting region of the pipe. It was also concluded that the crack in the barrier in these pipes occurred after completion of the FAT and sometime during the transportation, storage and subsequent installation of the pipes in the field. It was identified that the problem in the barrier resulted from an unknown thermo-mechanical loading condition of the pipe during this period, and also related to specific design features of some components in those end-fittings. The TapRoot Root Cause Analysis (RCA) tool was used to guide the investigation effort and consider all available data. Small and full-scale tests were performed to simulate and understand the end fitting design in the environments and conditions experienced during transport, installation and offshore testing. What is presented here is a brief outline of the incident and details of the subsequent investigation. The investigation was conducted over a period of 18 months with the participation of all parties involved in the design, manufacture, installation and operation of the flexibles. This paper summarises the investigation process followed, documents the results, discusses the results and outlines the conclusions and recommendations arising from this investigation.


2009 ◽  
Vol 9 (4) ◽  
pp. 1291-1298 ◽  
Author(s):  
D. Peila ◽  
C. Ronco

Abstract. The need for protection against rockfall has led to the development of different types of technological solutions that are able to both prevent blocks from detaching from rock walls and to control, intercept or deviate the blocks during movement. Of the many devices that are able to intercept and stop a block, one of the most frequently used is net fence. Many different types of full-scale tests have been carried out, with different test site geometries and procedures to study their behaviour and to certify these devices. This has led to a series of data and information that are not easy to compare. The recent endorsement, by the European Organization for Technical Approvals (EOTA), of a European Technical Approval Guideline (ETAG), which defines how to test and assess the performance of a net fence, is therefore a great innovation that will change both the market and the design procedures of these devices. The most important innovations introduced by this new guideline are here presented and discussed and a net fence design procedure for protection against rockfall is provided.


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