Introduction and Overview External Loads Design of Gravity Flow Pipes Design of Pressure Pipes Buried Pipe Products

Buried Pipe Design

Shear Tests of High- and Low-Strength Concrete Beams Without Stirrups

Finite elements in the analysis of pressure vessels and piping, an addendum: A bibliography (2001–2004)

The paper reports numerical model details and predictions of the end-of-construction performance for two instrumented and well-documented mechanically stabilized earth (MSE) walls. The walls were constructed as part of the highway SR-18 approach fills for a bridge near Seattle, Washington. The geogrid reinforced block face walls were modeled using a commercially available two-dimensional (2D) finite-difference program. The paper provides details on how material properties were selected from laboratory testing of wall components and how the computer modeling was carried out. The paper shows that predicted wall deformations and reinforcement strains were in reasonable agreement with measured data using both linear elastic-plastic and nonlinear elastic-plastic constitutive models for the soil. The geogrid reinforcement was simulated using a nonlinear load-strain-time secant stiffness model and cable elements. The paper compares numerical predictions of reinforcement loads at end of construction with ...

Numerical Modeling of the SR-18 Geogrid Reinforced Modular Block Retaining Walls

State-of-the-art on load testing of concrete bridges

Tests have been performed in a biaxial pipe test cell to develop baseline information on profiled pipe behavior under biaxial loading. These include a lined corrugated high-density polyethylene pipe and a helically wound ribbed polyvinyl chloride pipe. Results of the tests are utilized to examine the effectiveness of the two-dimensional methods of buried pipe analysis. Calculations of pipe responses by the two-dimensional finite element method and a set of simplified design equations are compared with the measurements of pipe strains and deflections. The study reveals that the two-dimensional finite element analysis can effectively be used to calculate pipe deflections and circumferential strains. The simplified equations appear suitable as design tools for standard buried thermoplastic pipe installations. Janbu’s nonlinear soil model with Mohr–Coulomb plasticity provided an effective simulation of the nonlinear soil behavior A study of pipes with low stiffness soil support under the haunches shows that t...

Two-Dimensional Analyses of Thermoplastic Culvert Deformations and Strains

This report contains the findings of a study to develop recommended design and construction specifications for metal and concrete large-span culverts. The report describes the research effort leading to the recommended specifications and includes information on field-testing and computer modeling. The methodology used to develop simplified design equations is also included. The material in this report will be of immediate interest to specification writers and to engineers concerned with the design and construction of large-span culverts.

Recommended specifications for large-span culverts

This report provides recommendations to revise the AASHTO LRFD Bridge Design Specifications relating to the distribution of live load to buried structures. The report details the development of simplified design equations (SDEs) for structural response based on three-dimensional (3D) analysis of 830 buried culverts. In addition, the report provides guidelines for conducting 2D and 3D modeling for design situations with conditions not covered by the SDEs. The material in this report will be of immediate interest to roadway and bridge designers.

Recommended Design Specifications for Live Load Distribution to Buried Structures

This report contains the findings of research performed to develop a recommended load and resistance factor design (LRFD) specification for thermoplastic pipe used in culverts and drainage systems for highway structures. The report details the research performed and includes a recommended LRFD design specification, a quality assurance specification for manufactured thermoplastic pipe, and the results of supporting analyses. Thus, the report will be of immediate interest to bridge and structural design engineers and materials engineers in state highway agencies, as well as to thermoplastic pipe suppliers.

Updated Test and Design Methods for Thermoplastic Drainage Pipe

This report summarizes a study of installation practices for buried (culvert) pipes. Current practice was reviewed through a literature search and a survey of users, manufacturers, and others involved in the use of buried pipes. Typical backfill materials were characterized through standard and variable effort compaction tests, CBR tests, penetration tests and one-dimensional compression tests. Standard classification systems were compared and standard groups of backfill materials were evaluated. The soil properties that were used to develop the AASHTO SIDD designs are proposed for use as standard properties for application to the installation of all types of pipes. The constrained modulus is proposed as the standard measure of soil stiffness replacing the empirical modulus of soil reaction. Laboratory soil box tests and full-scale field tests were conducted to investigate soil behavior during installation. Variables include pipe type (concrete, steel, plastic) and size [900 and 1,500 mm (36 and 60 in.)], in-situ soil condition, trench width, backfill type, compactive effort, haunching effort, and bedding condition. The tests showed that all of the backfill-related test variables have a significant effect on pipe behavior. Tests with controlled low-strength materials showed this to be an excellent type of backfill. Computer modelling demonstrated that the finite element analysis can effectively model installation effects as well as effects of the fill over the pipe. The elastic solution for behavior of buried pipe, developed by Burns and Richard, shows promise as a basis for a simplified design method. Recommendations for future practice include the use of soft bedding under the bottom of the pipe and of uncompacted fill over the top. Selection of trench width must consider the ability to place and compact backfill in the haunch zone and at the sides of the pipe. Hand tampers, sized differently for different backfills, were shown to be useful for providing haunching effort. It was shown that relatively small changes in backfill density can have significant effects on backfill stiffness. The project shows that pipe performance is controlled by installation practices. Implementation of a design process that realistically assesses how a project will be built, and construction that understands and implements the design, is imperative for successful long-term culvert performance.

https://rosap.ntl.bts.gov/view/dot/48814/dot_48814_DS1.pdf

Timothy J. McGrath

Papers

Two-Dimensional Analyses of Thermoplastic Culvert Deformations and Strains

Recommended specifications for large-span culverts

Recommended Design Specifications for Live Load Distribution to Buried Structures

Updated Test and Design Methods for Thermoplastic Drainage Pipe

Pipe interaction with the backfill envelope