Irradiated Steels Behavior in Long-Term Load Tests

2009 ◽  
pp. 584-584-15
Author(s):  
SN Votinov ◽  
VI Prochorov ◽  
VK Shamardin ◽  
AG Finko
Keyword(s):  
Load Tests

Theoretical bearing capacity of clay under shallow footings: verifying whether it is realistic

1988 ◽  
Vol 25 (1) ◽  
pp. 62-75
Author(s):  
Robert P. Chapuis ◽  
Vincent Silvestri ◽  
Michel Soulié
Keyword(s):  
Bearing Capacity ◽  
Major Influence ◽  
Clay Material ◽  
Short Term ◽  
Rigid Plastic ◽  
Long Term Conditions ◽  
True Value ◽  
Load Tests ◽  
Failure Conditions

Traditionally, the bearing capacity and the settlement of footings on clay are determined independently by theoretical analyses: the bearing capacity for short-term conditions and the settlement for long-term conditions. Bearing capacity methods usually assume that the clay has a rigid-plastic behaviour and they neglect prefailure deformations. Conventional settlement methods ignore failure conditions. However, field load tests give load–settlement curves in which it is impossible to dissociate settlement and bearing capacity.This paper examines whether the calculated theoretical qult is realistic. A long-term load–settlement curve can be easily calculated using an oedometric equation. The curve of soed/B versus load is a good approximation of the true long-term settlement curve and can be used to determine whether the (short-term) bearing capacity qu is realistic: if soed/B has a high value for a load smaller than the computed qu, it means that this qu is not a valid evaluation of the bearing capacity, the true value of which remains unknown. To establish when conventional analyses give erroneous bearing capacities four cases are analyzed, encompassing the influence of the compressibility of the clay material and the influence of downward groundwater gradients on the compressibility. The results show that groundwater conditions have a major influence upon the bearing capacity of highly compressible, slightly overconsolidated clays but practically no influence upon the bearing capacity of clays of low compressibility. Key words: shallow foundations, clay, deformability, bearing capacity, settlement.

An analysis of long-term pile load tests in permafrost from the Short Range Radar site foundations

2001 ◽  
Vol 38 (3) ◽  
pp. 441-460 ◽  
Author(s):  
Kevin W Biggar ◽  
Vivien Kong
Keyword(s):  
Short Range ◽  
Design Guidelines ◽  
Unfrozen Water ◽  
Detailed Knowledge ◽  
Unfrozen Water Content ◽  
Load Tests ◽  
Pile Load Tests ◽  
Ultimate Load Carrying Capacity ◽  
Term Creep

During the installation of the Short Range Radar (SRR) facilities at 35 sites across the Canadian Arctic, in excess of 7 000 piles were installed for the SRR foundations. A total of 137 pile load tests were performed during the SRR construction. Only a small number of these were installed external to the foundations and were loaded well in excess of design loads to attempt to determine their ultimate load carrying capacity. Only eight of these piles were loaded for extended durations (>12 h). This paper presents the results of these long-term load tests and compares the results with design guidelines based on allowable pile deformations and creep in ice-rich, saline permafrost. In nonsaline permafrost, at high normalized displacement rates (>30 year–1) the stresses on the piles at failure were less than those predicted by design guidelines for piles in ice-rich soil. At lower normalized displacement rates (<15 year–1) the failure stresses on the piles were reasonably well predicted by the design guidelines. Significant reductions in pile capacity were observed in ice-rich, saline permafrost. Without detailed knowledge of the unfrozen water content in the soil, however, prediction of the behaviour of the piles could only be bounded by current design guidelines.Key Words: permafrost, field pile testing, cold-temperature grout, long-term creep.

scholarly journals Long-term Deflections in Balanced Cantilever Prestressed Concrete Bridges

2009 ◽  
Vol 4 (1) ◽  
pp. 22
Author(s):  
Eltayeb Hassan Onsa ◽  
Elsafi Mohamed Adam ◽  
Abdalla Khogali Ahmed ◽  
Mohamed Elmontasir Elbagir
Keyword(s):  
Prestressed Concrete ◽  
Concrete Bridges ◽  
Live Load ◽  
Prestressed Concrete Bridges ◽  
Prestressing Force ◽  
Load Tests ◽  
The Moment ◽  
Aashto Lrfd ◽  
Made In

Long-term deflections in balanced cantilever prestressed concrete bridges are reviewed. Burri and Shambat Bridges are taken as cases study to calculate long-term deflection. The two bridges were constructed at Khartoum State in the years 1972 and 1962, respectively. Due to the shortage of the basic data regarding the two bridges the AASHTO-LRFD is used to estimate and calculate the missing data in the two bridges. The Moment Area method is used to calculate the long-term deflections due to the dead load, live load and prestressing force. The calculated long-term deflections are compared with measured live load deflections obtained from load tests made by a Chinese contractor requested to evaluate the two bridges. Remarkable differences between theoretical and measured deflection at the end of cantilevers are encountered. The differences are probably due to the basic assumptions made in the formulations of deflection calculations. Some adjustments in the long-term deflection formulae are suggested to bring the calculated deflections in compatibility with measured ones.

scholarly journals Short-term and long-term longitudinal load tests of wooden rods

2020 ◽  
Vol 939 ◽  
pp. 012080
Author(s):  
K A Varenik ◽  
A S Varenik ◽  
A V Kirillov ◽  
M V Shuvalov
Keyword(s):  
Short Term ◽  
Longitudinal Load ◽  
Load Tests

scholarly journals Early work load tests for evaluation of long-term prognosis of acute myocardial infarction.

Heart ◽  
1977 ◽  
Vol 39 (7) ◽  
pp. 758-763 ◽  
Author(s):  
A Granath ◽  
T Sodermark ◽  
T Winge ◽  
U Volpe ◽  
S Zetterquist
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Work Load ◽  
Load Tests ◽  
Long Term Prognosis

Concrete Creep and Shrinkage Effect Analysis Program Development

2013 ◽  
Vol 405-408 ◽  
pp. 850-855
Author(s):  
Fa Xiong Li ◽  
Jia Guo ◽  
Hou Qing Huang ◽  
Qian Liu
Keyword(s):  
Fortran Program ◽  
Analysis Program ◽  
Effect Analysis ◽  
User Subroutine ◽  
Shrinkage Effect ◽  
Program Language ◽  
History Of ◽  
Load Tests ◽  
Creep And Shrinkage

In order to analysis of concrete based on ABAQUS, A creep and shrinkage of concrete analysis program TDPA was developed. Firstly, the theory of creep and shrinkage effect of concrete was introduced. with the help of a Dirichlet series properties, creep stepwise recursive method was introduced to avoid stress history of large capacity storage; Secondly, using three user subroutine interface USDFLD, GETVRM, UEXPAN provided by ABAQUS, analysis program TDPA was developed by Fortran program language; Finally, typical long-term load tests of pre-stressed concrete and steel concrete composite members long term tests were selected to prove the reliability of TDPA. Research results show that: the TDAP has high applicability and reliability. It is suitable for a variety of creep and shrinkage prediction model, and provides an effective method for creep and shrinkage of concrete analysis on ABAQUS platform.

Fracture and long-term aging characteristics of GFRP clamping plates for improved movable weirs

2018 ◽  
Vol 27 (3) ◽  
pp. 143-154
Author(s):  
Ri-On Oh ◽  
Chan-Gi Park
Keyword(s):  
Residual Strength ◽  
Tap Water ◽  
Fracture Load ◽  
Fiber Reinforced Polymer ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Aging Properties ◽  
Control Load ◽  
Load Tests

In this study, the durability of movable weirs was improved by replacing steel clamping plates with glass fiber-reinforced polymer (GFRP) material. Because the clamping plates of movable weirs are always in contact with water, the service life of weirs is reduced due to corrosion. Other environmental conditions also degrade movable weirs, such as exposure to continuous inundation, dry environments, repeated dry and wet conditions, and chemical environments. This study evaluated the absorption, fracture, and long-term aging properties of GFRP clamping plates for improved movable weirs. Absorption increased with immersion time in 60°C tap water, sodium sulfate (Na2SO4) solution, or calcium chloride (CaCl2) solution. However, the total absorption for 50 days and 100 days exposure was low, less than 0.50% and 0.62%, respectively. In fracture load tests, the GFRP clamping plates showed the largest reduction in strength after exposure to the CaCl2 solution; 70% and 67% of the control load were retained for exposures of 50 days and 100 days, respectively. After exposure to both tap water and the Na2SO4 solution, the GFRP clamping plates showed residual strengths of 77% and 69% after 50 days and 100 days exposure, respectively. The GFRP clamping plates showed 74% and 71% residual strength after exposure to repeated freeze–thaw environments for 50 days and 100 days, respectively, and 80% residual strength after exposure to all other environments for 50 days or 100 days. Both vertical and horizontal cracks were generated before fracture after exposure to an environment involving direct contact with moisture. Without moisture, only horizontal cracks were generated before fracture.

scholarly journals TESTING OF SOIL IMPROVEMENT BELOW A HALL FLOOR

2017 ◽  
Vol 10 ◽  
pp. 52
Author(s):  
Monika Súlovská ◽  
Peter Turček ◽  
Zuzana Štefunková
Keyword(s):  
Static Load ◽  
Weather Conditions ◽  
Soil Improvement ◽  
Construction Work ◽  
North West ◽  
Load Tests ◽  
Base Course ◽  
Required Quality

Construction of a hall situated in North-West Slovakia was prepared in winter. After finishing an elementary ground adaptation in February there were extreme weather conditions: the precipitation exceeded by over 300 % the normal long term measured amount. This indisposition of climate led to a stopping of the construction work. Checks on the required quality of the base course using static load tests showed a failure in performance of compaction. The sampling and laboratory testing of the original and the improved soils are discussed in the paper.

scholarly journals Monitoring of Structures by a Laser Pointer: Dynamic Measurement of Displacements of a Bridge

2017 ◽  
Author(s):  
Serena Artese ◽  
Vladimiro Achilli ◽  
Raffaele Zinno
Keyword(s):  
Dynamic Measurement ◽  
Dynamic Monitoring ◽  
Bridge Structure ◽  
Displacement Monitoring ◽  
Laser Pointer ◽  
Technical Parameters ◽  
Vertical Displacements ◽  
Load Tests ◽  
Heavy Truck

Vertical displacements are among the most important technical parameters to evaluate the health status of a bridge structure and to verify its bearing capacity. Several methods, both conventional and innovative, are used for structural displacement monitoring; no one of these does allow, at the same time, precision, automation, long term and dynamic monitoring without using high cost instrumentation. The proposed system makes use of a common laser pointer and image processing. The measurement of the lowering is obtained by analyzing the single frames of a HD video of the laser beam imprint projected on a flat target. For the processing of images, a code was developed in Matlab&reg; that provides the instantaneous displacement of a bridge, charged by a mobile load. An important feature is the synchronization of the load positioning, obtained by GNSS receiver or by a video. After the calibration procedures, a test was carried out during the movements of a heavy truck maneuvering on a bridge. Data acquisition synchronization allowed to relate the position of the truck on the deck to the displacements. The results show high accuracy and demonstrate that the method is suitable for dynamic load tests, ever more adopted for the bridge controls and monitoring.

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