Field Measurements and Predictions of Concrete Temperatures in Large Diameter Drilled Shafts in Hawaii

2011 ◽  
Author(s):  
Xiaobin Lin ◽  
Robin M. Lim
Keyword(s):  
Large Diameter ◽  
Field Measurements ◽  
Drilled Shafts

Establishing and Satisfying Thermal Requirements for Drilled Shaft Concrete Based on Durability Considerations

2021 ◽  
pp. 036119812199635
Author(s):  
Andrew Z. Boeckmann ◽  
Zakaria El-tayash ◽  
J. Erik Loehr
Keyword(s):  
Mechanical Response ◽  
Large Diameter ◽  
Thermal Cracking ◽  
Drilled Shafts ◽  
Maximum Temperature ◽  
Design Parameters ◽  
Mass Concrete ◽  
Temperature Differential ◽  
Thermal Requirements ◽  
Ettringite Formation

Some U.S. transportation agencies have recently applied mass concrete provisions to drilled shafts, imposing limits on maximum temperatures and maximum temperature differentials. On one hand, temperatures commonly observed in large-diameter drilled shafts have been observed to cause delayed ettringite formation (DEF) and thermal cracking in above-ground concrete elements. On the other, the reinforcement and confinement unique to drilled shafts should provide resistance to thermal cracking, and the provisions that have been applied are based on dated practices for above-ground concrete. This paper establishes a rational procedure for design of drilled shafts for durability requirements in response to hydration temperatures, which addresses both DEF and thermal cracking. DEF is addressed through maximum temperature differential limitations that are based on concrete mix design parameters. Thermal cracking is addressed through calculations that explicitly consider the thermo-mechanical response of concrete for predicted temperatures. Results from application of the procedure indicate consideration of DEF and thermal cracking potential for drilled shafts is prudent, but provisions that have been applied to date are overly restrictive in many circumstances, particularly the commonly adopted 35°F maximum temperature differential provision.

Field Measurements of Mean Velocity Characteristics of a Large-Diameter Swirling Jet

2010 ◽  
Vol 136 (9) ◽  
pp. 642-650 ◽  
Author(s):  
D. M. Lewis ◽  
M. F. Lambert ◽  
M. D. Burch ◽  
J. D. Brookes
Keyword(s):  
Large Diameter ◽  
Field Measurements ◽  
Mean Velocity ◽  
Swirling Jet

Design of large-diameter drilled shafts for the Northumberland Strait bridge project

1997 ◽  
Vol 34 (4) ◽  
pp. 580-587 ◽  
Author(s):  
D J Walter ◽  
W J Burwash ◽  
R A Montgomery
Keyword(s):  
Large Diameter ◽  
Drilled Shafts

Field measurements and analysis of a large-diameter flexible culvert

1993 ◽  
Vol 30 (1) ◽  
pp. 135-145 ◽  
Author(s):  
P. M. Byrne ◽  
T. Srithar ◽  
C. B. Kern
Keyword(s):  
Finite Element ◽  
Soil Structure ◽  
Soil Cover ◽  
Large Diameter ◽  
Field Measurements ◽  
Nonlinear Finite Element ◽  
Original Structure ◽  
Soil Arching ◽  
Element Analysis ◽  
Soil Arch

This paper describes field measurements and analysis carried out on the Elkhart Creek soil–arch culvert structure in British Columbia, Canada. The structure has a span of 13.4 m, a rise of 7.3 m, and a soil cover of 9.6 m. The original structure collapsed during backfilling in October 1987. A new structure of the same design was built in the fall of 1989, and because of controversy regarding the design thrust value, it was instrumented to measure thrust and displacements in the arch. Displacements and stresses in the soil were also measured. The measured thrust values were much lower than expected and indicated that significant positive soil arching occurred, similar to that observed at the Vieux Comptoir soil–stucture in Quebec in 1975. A nonlinear finite element analysis of the soil–structure system was carried out simulating the construction procedures used, and the computed response was compared with the measurements. The computed and observed responses were in reasonable agreement in all aspects, namely thrust, displacements, and soil stresses, provided an allowance was made for slip at the bolted connections. Key words : culvert, finite element, arching, stress, displacements.

scholarly journals Pipes to Earth's subsurface: the role of atmospheric conditions in controlling air transport through boreholes and shafts

2018 ◽  
Vol 9 (3) ◽  
pp. 1141-1153 ◽  
Author(s):  
Elad Levintal ◽  
Nadav G. Lensky ◽  
Amit Mushkin ◽  
Noam Weisbrod
Keyword(s):  
Large Diameter ◽  
Absolute Humidity ◽  
Field Measurements ◽  
Barometric Pressure ◽  
Atmospheric Temperature ◽  
Air Transport ◽  
Atmospheric Conditions ◽  
Air Masses ◽  
Diurnal Cycles

Abstract. Understanding air exchange dynamics between underground cavities (e.g., caves, mines, boreholes, etc.) and the atmosphere is significant for the exploration of gas transport across the Earth–atmosphere interface. Here, we investigated the role of atmospheric conditions in controlling air transport inside boreholes using in situ field measurements. Three geometries were explored: (1) a narrow and deep shaft (0.1 m wide and 27 m deep), ending in a large underground cavity; (2) the same shaft after the pipe was lowered and separated from the cavity; and (3) a deep large-diameter borehole (59 m deep and 3.4 m wide). Absolute humidity was found to be a reliable proxy for distinguishing between atmospheric and cavity air masses (mainly during the winter and spring seasons) and thus to explore air transport through the three geometries. Airflow directions in the first two narrow-diameter geometries were found to be driven by changes in barometric pressure, whereas airflow in the large-diameter geometry was correlated primarily with the diurnal cycles of ambient atmospheric temperature. CO2 concentrations of ∼2000 ppm were found in all three geometries, indicating that airflow from the Earth's subsurface into the atmosphere may also be significant in the investigation of greenhouse gas emissions.

Large Diameter Double Underreamed Drilled Shafts

1983 ◽  
Vol 109 (8) ◽  
pp. 1082-1098 ◽  
Author(s):  
Ray E. Martin ◽  
Raymond A. DeStephen
Keyword(s):  
Large Diameter ◽  
Drilled Shafts

The Numerical Analysis and Field Measurements of the Shield Tunnel Passing through the Pipeline Groups

2012 ◽  
Vol 226-228 ◽  
pp. 1488-1494
Author(s):  
Guan Shui Liu ◽  
Lian Wei Sun ◽  
Bo Wang ◽  
Shi Ming Wu ◽  
Cheng Po Hong ◽  
...  
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Numerical Model ◽  
Water Pressure ◽  
Large Diameter ◽  
Field Measurements ◽  
Numerical Results ◽  
Shield Tunnel ◽  
Sewer Pipes

In this work, research was carried out based on the shield tunnel of metro line 1 in Hangzhou. The construction of this tunnel beneath the sewage pipelines, which have large diameter with water pressure. The project studied in this treatise is relatively rare in China in terms of sewer pipes, the number of sewers, spacing between shield and sewers and the crossing times. A numerical model was established to analyze the construction of metro across the sewage pipelines with water pressure, taking the interactions between tunnel, pipelines and soil into account. The stress of pipelines, settlement of pipelines and ground during the crossing process were calculated. The finite element results were compared with measured results to verify the reliability of numerical results. Some meaningful results were achieved.

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