Circular precast concrete manholes: experimental investigation

2011 ◽  
Vol 38 (3) ◽  
pp. 319-330 ◽  
Author(s):  
Reem Sabouni ◽  
M.H. El Naggar
Keyword(s):  
Large Scale ◽  
Precast Concrete ◽  
Technical Information ◽  
Experimental Program ◽  
Traffic Loading ◽  
Sanitary Sewer ◽  
Testing Facility ◽  
Load Tests ◽  
Geotechnical Testing ◽  
The University

Circular precast concrete manholes are widely used in sanitary sewer and storm water systems. The lack of detailed technical information on them and the conservatism of their governing codes and standards call for a detailed investigation on them. The main objectives of this paper are to evaluate the state of strains in the precast concrete manhole and state of stresses in the soil beneath the base to be used in developing enhanced guidelines for the design of their bases. Three full-scale circular precast concrete manholes, two 1200 mm in diameter and one 1500 mm in diameter, were tested in the large-scale geotechnical testing facility (LSGTF) at the University of Western Ontario. Only one 1200 mm manhole base was reinforced. Twenty seven load tests were performed on the manholes, which involved loads representing the Ontario truck loads incorporated in the Canadian Highway Bridge Code. None of the manhole sections tested in the experimental program experienced any cracks. The test results showed that traffic loading had a small effect on the pressure under the manhole base. All three specimens could withstand the critical Ontario truck loads, even the non-reinforced ones.

Volume Displacement Effects on Pile Capacity in Loose Sand

1973 ◽  
Vol 10 (4) ◽  
pp. 645-647
Author(s):  
Eli I. Robinsky ◽  
Christopher B. H. Cragg
Keyword(s):  
Bearing Capacity ◽  
Large Scale ◽  
Loose Sand ◽  
Soil Pressure ◽  
Pile Capacity ◽  
University Of Toronto ◽  
Testing Facility ◽  
Large Scale Testing ◽  
The University ◽  
Displacement Effects

Preliminary tests in the new large-scale testing facility at the University of Toronto reveal that bearing capacity on a pile volume basis is more efficiently developed by a long slender pile or a group of short slender piles than by a pile of larger diameter. The authors attribute this to increased arching in the soil around the pile of greater volume displacement, believing arching buffers the pile from the effects of lateral soil pressure.

Axial response of piles in electrically treated clay

1999 ◽  
Vol 36 (3) ◽  
pp. 418-429 ◽  
Author(s):  
M Abdel-Meguid ◽  
M H El Naggar ◽  
J Q Shang
Keyword(s):  
High Voltage ◽  
Large Scale ◽  
Axial Loading ◽  
Soil Improvement ◽  
Pullout Capacity ◽  
Axial Capacity ◽  
Testing Facility ◽  
Load Tests ◽  
Pile Load Tests ◽  
Marine Clays

Improvement of the shear strength of soft clayey soils around steel pipe piles using high-voltage electrokinetics is investigated in the present study. The experimental setup of a large-scale testing facility is described. Four model piles were installed in two identical cylinders filled with simulated marine sediment. Five electrically insulated electrodes were installed close to the piles to apply a high-voltage electric field in the test cylinder. Negative direct current voltages of -20, -30, and -10 kV were applied in three phases, respectively, for 33 days in the treatment cylinder. Axial compression and pullout pile load tests were performed and the results were compared for both cylinders after each phase of treatment. The pile response is presented in terms of the experimental load deflection curves. It is observed that the axial capacity was increased 30, 29, and 8% after the first, second, and third treatment phases, respectively. The pullout capacity was increased due to the treatment by 11, 23, and 12% after the first, second, and third treatment phases, respectively. Further development of this technique may provide potential solutions for the improvement of soft marine clays, and ultimately it could be applied in the field to rehabilitate existing offshore foundations.Key words: electrokinetics, piles, marine clays, soil improvement, bearing capacity, axial loading.

A Database for the Experimental Study of Earthquake-Induced Liquefaction and Lateral Spreading in Sands

2016 ◽  
Vol 32 (2) ◽  
pp. 1261-1279
Author(s):  
Tarek Abdoun ◽  
Waleed El-Sekelly ◽  
Ricardo Dobry ◽  
Sabanayagam Thevanayagam ◽  
Marcelo Gonzalez
Keyword(s):  
Large Scale ◽  
Rensselaer Polytechnic Institute ◽  
Lateral Spreading ◽  
Soil Behavior ◽  
Centrifuge Testing ◽  
Geotechnical Centrifuge ◽  
Testing Facility ◽  
Large Scale Testing ◽  
Materials Used ◽  
The University

Centrifuge and large-scale testing in geotechnical engineering are very useful tools for modeling soil behavior under different loading conditions, particularly under earthquake loading. The paper presents an extensive database of nine centrifuge and large-scale liquefaction experiments performed both at the geotechnical centrifuge testing facility at Rensselaer Polytechnic Institute (RPI) and the large-scale testing facility at the University at Buffalo (UB). The database described herein was generated using the NEEShub online DataStore tool under the name “CENSEIS: Centrifuge and Large (Full)-Scale Modeling of Seismic Pore Pressures in Sands” (DOI: http://dx.doi.org/10.4231/D3GF0MX4F ). The paper discusses the tools and materials used in the experiments along with an explanation of each item in the database. Sample analyses are also presented in the paper to give an insight on the capabilities of the database for numerical and analytical applications. The paper is concluded with some possible applications along with tips and limitations of the database.

The 1-MeV Electron Microscope Installation at the University of Colorado

1973 ◽  
Vol 31 ◽  
pp. 8-9 ◽  
Author(s):  
Mircea Fotino
Keyword(s):  
Electron Microscopy ◽  
Developmental Biology ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
National Institutes Of Health ◽  
Experimental Program ◽  
University Of Colorado ◽  
Transmission Electron ◽  
The University ◽  
Research Resources

A new 1-MeV transmission electron microscope (Model JEM-1000) was installed at the Department of Molecular, Cellular and Developmental Biology of the University of Colorado in Boulder during the summer and fall of 1972 under the sponsorship of the Division of Research Resources of the National Institutes of Health. The installation was completed in October, 1972. It is installed primarily for the study of biological materials without many of the limitations hitherto unavoidable in standard transmission electron microscopy. Only the technical characteristics of the installation are briefly reviewed here. A more detailed discussion of the experimental program under way is being published elsewhere.

SOCIAL PROJECT AS A PLATFORM FOR THE IMPLEMENTATION OF PROFESSIONAL SKILLS OF FUTURE INFORMATICS TEACHERS

2019 ◽  
pp. 16-22
Author(s):  
E. V. Klimenko ◽  
N. S. Buslova
Keyword(s):  
Large Scale ◽  
Modern Society ◽  
Professional Competencies ◽  
Future Teachers ◽  
Professional Skills ◽  
Knowledge And Skills ◽  
Theoretical Reasoning ◽  
Social Project ◽  
The University

The article is devoted to the consideration of ways to solve one of the actual problems in theory and methodology of training and upbringing — the problem of developing professional skills of future informatics teacher. As a way to adapt students to the profession, the possibility of their involvement in social designing was chosen. Participation in social projects contributes to the approbation and introduction of new forms and methods in teaching informatics. Expanding the experience of future teachers in carrying out large-scale events contributes to the formation of a socially adapted personality competitive in modern society. The potential of a social project in consolidating the knowledge and skills obtained during the theoretical training at the university is indicated. In the article, theoretical reasoning is accompanied by examples of real social projects and activities aimed at the formation of professional competencies of future informatics teachers.

Disruptive innovation and operationalization in local and sustainable food systems: Examining the University of Toronto-Local Food Plus partnership

2019 ◽  
Vol 6 (1) ◽  
pp. 120-139
Author(s):  
Lori Stahlbrand
Keyword(s):  
Food Systems ◽  
Large Scale ◽  
Food System ◽  
Local Food ◽  
Disruptive Innovation ◽  
Government Support ◽  
Sustainable Food ◽  
University Of Toronto ◽  
The University

This paper traces the partnership between the University of Toronto and the non-profit Local Food Plus (LFP) to bring local sustainable food to its St. George campus. At its launch, the partnership represented the largest purchase of local sustainable food at a Canadian university, as well as LFP’s first foray into supporting institutional procurement of local sustainable food. LFP was founded in 2005 with a vision to foster sustainable local food economies. To this end, LFP developed a certification system and a marketing program that matched certified farmers and processors to buyers. LFP emphasized large-scale purchases by public institutions. Using information from in-depth semi-structured key informant interviews, this paper argues that the LFP project was a disruptive innovation that posed a challenge to many dimensions of the established food system. The LFP case study reveals structural obstacles to operationalizing a local and sustainable food system. These include a lack of mid-sized infrastructure serving local farmers, the domination of a rebate system of purchasing controlled by an oligopolistic foodservice sector, and embedded government support of export agriculture. This case study is an example of praxis, as the author was the founder of LFP, as well as an academic researcher and analyst.

Investigation of Grouted Coupler Connection Details for Accelerated Bridge Construction

2021 ◽  
pp. 036119812199939
Author(s):  
Brent Phares ◽  
Yoon-Si Lee ◽  
Travis K. Hosteng ◽  
Jim Nelson
Keyword(s):  
Crack Width ◽  
High Performance ◽  
Static Load ◽  
High Performance Concrete ◽  
Precast Concrete ◽  
Chloride Penetration ◽  
Load Testing ◽  
Test And Evaluation ◽  
Load Tests ◽  
Precast Elements

This paper presents a laboratory investigation on the performance of grouted rebar couplers with the connection details similar to those utilized on the precast concrete elements of the Keg Creek Bridge on US 6 in Iowa. The testing program consisted of a series of static load tests, a fatigue test, and evaluation of the chloride penetration resistance of laboratory specimens. The goal of this testing was to evaluate the ability of the grouted rebar couplers to develop flexural capacity at the joint between the precast elements as well as the durability of the connection. For structural load testing, seven full-scale specimens, each with #14 epoxy-coated rebars spliced by epoxy-coated grouted couplers, were fabricated and tested in three different loading cases: four-point bending, axial tension plus bending, and a cyclic test of the system in bending. The static load testing demonstrated that the applied axial load had a minimal effect on the formation of cracks and overall performance of the connection. When ultra-high performance concrete was used as a bedding grout, the initiation of crack was slightly delayed but no considerable improvement was observed in the magnitude of the crack width during loading or the crack closure on unloading. The results of the seventh specimen, tested in fatigue to 1 million cycles, showed little global displacement and crack width throughout the test, neither of which expanded measurably. No evidence of moisture or chloride penetration was detected at the grouted joint during the 6-month monitoring.

THE CONNECTION MACHINE IN A UNIVERSITY ENVIRONMENT: GESAMTHOCHSCHULE WUPPERTAL

1993 ◽  
Vol 04 (01) ◽  
pp. 137-141
Author(s):  
KLAUS SCHILLING
Keyword(s):  
Parallel Computing ◽  
Computer Science ◽  
Large Scale ◽  
Early History ◽  
Short Account ◽  
University Environment ◽  
Connection Machine ◽  
The University

A short account is presented on the early history, the intentions and the development of large scale parallel computing at the University of Wuppertal. It might serve as an illustration how common activities between computational and computer science can be stimulated, in the university environment.

Two-dimensional elastic pseudo-spectral modeling of wide-aperture seismic array data with application to the Wichita Uplift-Anadarko Basin region of southwestern Oklahoma

1990 ◽  
Vol 80 (6A) ◽  
pp. 1677-1695 ◽  
Author(s):  
Ik Bum Kang ◽  
George A. McMechan
Keyword(s):  
Large Scale ◽  
Deep Structure ◽  
Sedimentary Basins ◽  
P Wave ◽  
Two Dimensional ◽  
Anadarko Basin ◽  
Near Surface ◽  
University Of Texas ◽  
Wide Aperture ◽  
The University

Abstract Full wave field modeling of wide-aperture data is performed with a pseudospectral implementation of the elastic wave equation. This approach naturally produces three-component stress and two-component particle displacement, velocity, and acceleration seismograms for compressional, shear, and Rayleigh waves. It also has distinct advantages in terms of computational requirements over finite-differencing when data from large-scale structures are to be modeled at high frequencies. The algorithm is applied to iterative two-dimensional modeling of seismograms from a survey performed in 1985 by The University of Texas at El Paso and The University of Texas at Dallas across the Anadarko basin and the Wichita Mountains in southwestern Oklahoma. The results provide an independent look at details of near-surface structure and reflector configurations. Near-surface (<3 km deep) structure and scattering effects account for a large percentage (>70 per cent) of the energy in the observed seismograms. The interpretation of the data is consistent with the results of previous studies of these data, but provides considerably more detail. Overall, the P-wave velocities in the Wichita Uplift are more typical of the middle crust than the upper crust (5.3 to 7.1 km/sec). At the surface, the uplift is either exposed as weathered outcrop (5.0 to 5.3 km/sec) or is overlain with sediments of up to 0.4 km in thickness, ranging in velocity from 2.7 to 3.4 km/sec, generally increasing with depth. The core of the uplift is relatively seismically transparent. A very clear, coherent reflection is observed from the Mountain View fault, which dips at ≈40° to the southwest, to at least 12 km depth. Velocities in the Anadarko Basin are typical of sedimentary basins; there is a general increase from ≈2.7 km/sec at the surface to ≈5.9 km/sec at ≈16 km depth, with discontinuous reflections at depths of ≈8, 10, 12, and 16 km.

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