Field Performance of Instrumented Concrete Pipe Under Deep Burial

1997 ◽  
Vol 1594 (1) ◽  
pp. 224-234 ◽  
Author(s):  
Glenn A. Hazen ◽  
Shad M. Sargand ◽  
Mohammed Haque ◽  
John O. Hurd
Keyword(s):  
Reinforced Concrete ◽  
Computer Program ◽  
Field Performance ◽  
Concrete Pipes ◽  
Deep Burial ◽  
Direct Design ◽  
Concrete Pipe ◽  
Design Calculations ◽  
Buried Concrete ◽  
Contact Pressures

Two 1.524-m-diameter, reinforced concrete pipes were instrumented to compare field results with design calculations. A computer program, Standard Installation Direct Design, developed by the American Concrete Pipe Association was used to design the pipe. Instrumented pipes were completely monitored until 11.9 m of cover had been placed. Measurements of soil contact pressures and vertical and horizontal deflections continued for 6 months. The computer-simulated and observed responses of the buried concrete pipe installations were compared. Pipe contact pressures measured at the invert were much smaller than those assumed from calculations of thrust and moment. Design moments were conservative compared with the experimentally measured values. Thrusts are difficult to calculate accurately and show large experimental variations.

A new test method for evaluating the long-term performance of fiber-reinforced concrete pipes

2019 ◽  
Vol 23 (7) ◽  
pp. 1336-1349 ◽  
Author(s):  
Fouad T Al Rikabi ◽  
Shad M Sargand ◽  
Issam Khoury ◽  
John Kurdziel
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Steel Reinforcement ◽  
Fiber Reinforced Concrete ◽  
Synthetic Fiber ◽  
Concrete Pipes ◽  
Concrete Pipe ◽  
Long Term Performance ◽  
Term Performance

Synthetic fibers have been used recently to minimize the need for steel reinforcement in the concrete pipe to enhance their ductility. However, synthetic fiber has properties that may change over time due to its viscoelastic behavior. The objective of this study is to investigate the long-term performance of fiber-reinforced concrete pipes using a new test frame. A three-dimensional finite element model was created for the long-term testing frame to ensure its compliance with the American Society for Testing and Materials requirement. The finite element results showed that the testing frame successfully transferred the load to the concrete as the pipe cracked at the location where high flexural stresses are expected. Concrete pipe reinforced with synthetic fiber dosage of 9 kg/m3 along the steel reinforcement area of 5.7 cm2/m was tested to evaluate the concrete pipe system performance. The pipe was tested under two load stages for 120 days each. Load stages 1 and 2 included applying 40% and 70% of the ultimate load obtained by the authors in a previous study, respectively. The strain and deflection increased linearly within 5 days of applying the load and then leveled off. The pipe showed a slight increase in the crack width and deflection, indicating that fiber creep did not have a significant impact on the long-term performance of the concrete pipe. Also, it was observed that strain values surpassed those for plain concrete material, suggesting that including synthetic fiber in the concrete pipe mix enhanced the pipe ductility.

The Determination of Prestress for Reinforced Concrete Pipes Based on Elasticity

2011 ◽  
Vol 213 ◽  
pp. 510-514
Author(s):  
Rong He ◽  
Wei He ◽  
Heng Xiang Zheng
Keyword(s):  
Reinforced Concrete ◽  
Critical Conditions ◽  
Elastic Model ◽  
Concrete Pipes ◽  
Inner Pressure ◽  
Concrete Pipe ◽  
Stress Boundary Condition ◽  
Theory Result ◽  
Stress Boundary

Based on elasticity, an elastic model was used to derivate the stress function and the stress expressions. According to the stress boundary condition and the geometry dimension of a cylinder-cross-section pipe, the constants are determined. First supposed the pipe were empty and the inner pressure were zero, the maximum prestress for the reinforced concrete pipe was determinate. Second, supposed the liquid pressure was the maximum, the model was used to determinate the minimum prestress. Combined the two critical conditions, the reasonable range of prestress for reinforced concrete pipe was got. In designing, the prestress must be consistent with it to prevent the concrete from crushing or bursting. At last, some differences between the theory result and the fact were pointed out to guide the application of the model.

scholarly journals Performance Evaluation of Buried Concrete Pipe Considering Soil Pressure and Crack Propagation Using 3D Finite Element Analysis

2021 ◽  
Vol 11 (7) ◽  
pp. 3292
Author(s):  
Hoki Ban ◽  
Seungjun Roh ◽  
Won-Jun Park
Keyword(s):  
Finite Element ◽  
Crack Propagation ◽  
Environmental Conditions ◽  
Soil Pressure ◽  
Concrete Pipes ◽  
Pressure Distributions ◽  
Concrete Pipe ◽  
Backfill Materials ◽  
Adjacent Soil ◽  
Buried Concrete

Numerous factors affect the soil pressure distributions around buried pipes, including the shape, size, and stiffness of the pipe, burial depth, and the stiffness of the surrounding soil. Additionally, to some extent, a pipe can benefit from the soil arching effect, where the overburden and surcharge pressure at the crown can be supported by the adjacent soil. As a result, a buried pipe only needs to support the portion of the load that is not transferred to the adjacent soil. This paper presents numerical investigations of the soil pressure distributions around buried concrete pipes and crack propagation under different environmental conditions, such as loading, saturation level, and the presence of voids. To this end, a nonlinear elastoplastic model for backfill materials was implemented using finite element software and a user-defined subroutine. Three different backfill materials and two different native soils were selected to examine the material-specific behaviors of concrete pipes, including soil pressure distributions and crack propagation. For each backfill material, the effects of the loading type, groundwater, and voids were investigated. These simulation results provide helpful information regarding pressure redistribution and buried concrete pipe behavior under various environmental conditions.

scholarly journals Cracks analysis in the reinforced concrete pipes

2017 ◽  
Vol 12 (2) ◽  
pp. 88-93 ◽  
Author(s):  
Lidia Buda-Ozog ◽  
Izabela Skrzypczak ◽  
Joanna Kujda
Keyword(s):  
Reinforced Concrete ◽  
Load Capacity ◽  
Experimental Studies ◽  
Concrete Pipes ◽  
Current State ◽  
Concrete Pipe ◽  
Basic Parameters ◽  
Numerical Research ◽  
State Of Research ◽  
Geometrical Dimensions

In this paper, the analysis of cracking due to tensile stress in a reinforced concrete pipe is presented. The tensile strength of concrete in case of the member of a high relative curvature is significantly different from the strength of uncurved elements. The current state of research indicates that only methods of nonlinear fracture mechanics lead to a satisfactory agreement between the results of calculations and experimental studies, and allow for compiling correctly the influence of basic parameters of stretched concrete and geometrical dimensions on the load capacity of crush pipes made from concrete. Obtaining consistent results of experimental and numerical research is still a very complicated issue. This paper presents the results of the experimental investigation performed on three pipes and the numerical model of the analysed element of the pipes made using the ATENA (Advanced Tool for Engineering Nonlinear Analysis) program. The numerical analyses of cracks were compared with the results of experimental studies.

Development of a new class of precast concrete pipes - an experimental evaluation

2007 ◽  
Vol 34 (7) ◽  
pp. 885-889 ◽  
Author(s):  
H El Naggar ◽  
E N Allouche ◽  
M H. El Naggar
Keyword(s):  
Experimental Evaluation ◽  
Solid Wall ◽  
Research Effort ◽  
Precast Concrete ◽  
Load Test ◽  
Added Value ◽  
Structural Performance ◽  
Concrete Pipes ◽  
Concrete Pipe ◽  
Cellular Concrete

Concrete pipes represent the backbone of the municipal storm and wastewater collection systems of Ontario, Canada. Industry and academia partnered on a research effort that aimed at developing new precast-concrete pipe products that provide added value to the final user in comparison with existing products. This paper describes a full-scale experimental evaluation of the design, manufacturing, and performance aspects of a "cellular" concrete pipe, a precast concrete pipe in which multiple continuous conduits were incorporated within its wall. Two fully-instrumented prototype segments of the proposed cellular concrete pipe were manufactured using standard dry-cast manufacturing procedures. The pipe segments were subjected to a D-load test to evaluate their structural performance. The observed structural performance was found to be comparable to solid-wall specimens, particularly when a four-conduit configuration was used. Of the six materials used as conduits, PVC and aluminum were found to perform the best. The presence of the conduits appears to delay the on-set of major cracks, thus increasing the D-load value. Key words: precast, concrete, pipe, experimental, conduit system, trenchless construction methods.

Fire Behaviors of Restrained RC Beams with Slab

2010 ◽  
Vol 163-167 ◽  
pp. 1445-1450
Author(s):  
Gui He Tang ◽  
Bo Wu
Keyword(s):  
Reinforced Concrete ◽  
Computer Program ◽  
Axial Force ◽  
Stiffness Ratio ◽  
Rc Beams ◽  
Slab Width ◽  
Standard Fire ◽  
Rotational Restraint ◽  
Simulation Results ◽  
In Fire

Using the computer program SAFIR, the behaviors of restrained reinforced concrete (RC) beams with slab exposed to ISO834 standard fire are analyzed. The influences of three parameters (i.e., width of slab, axial restraint stiffness ratio, and rotational restraint stiffness ratio) on the beams’ behaviors in fire are investigated. Simulation results show that: (a) the axial force in the slab is much larger than that in the beam on the whole; (b) after 0.5 hour of heating the axial force in the slab decreases gradually with an increasing of the slab width ranging from 1.0 m to 2.5 m, but the influence of the slab width ranging from 1.0 m to 2.5 m on the axial force in the beam is limited; and (c) the effect of the rotational restraint stiffness ratio on the axial force in the beam/slab is very limited, but the beam’s peak hogging moment increases gradually with an increasing of the rotational restraint stiffness ratio.

Sign in / Sign up

Export Citation Format

Share Document