2021

Josiah Beakley, American Concrete Pipe Association
Riley Dvorak, Forterra
Kevin Western, Minnesota Department of Transportation

Beginning in 2018, the precast concrete pipe producers of the Minnesota Concrete Pipe Association (MnCPA) worked with the Minnesota Department of Transportation (MnDOT) to update the standards for reinforced concrete arch pipe.  The MnDOT standard plates include steel reinforcement areas for both circumferential steel and transverse steel (stirrups) where required.  The latest MnDOT standards include pipe classes in accordance with AASHTO M206 (or ASTM C506) as well as some larger sizes and higher strength classes that are not included in the AASHTO standard.  The reinforcement designs for these larger sizes were performed in accordance with the 8 th Edition of the AASHTO LRFD Bridge Design Specifications and were formulated to encompass the worst of either the loads from the field installation, or the testing loads in three-edge bearing.  The three-edge bearing test requirements tended to govern the required steel area for transverse reinforcement.  However, the field conditions governed the extent to which the transverse reinforcement needs to extend out from the invert of the pipe.

Niyazi Özgür Bezgin (ozgur.bezgin@istanbul.edu.tr), Istanbul Universitesi, Cerrahpasa

Istiklal Street, located in the historic Beyoglu District of Istanbul began to develop in the second half of 18th Century. A tramway served along the middle of the street beginning in 1883 until it relinquished its place to vehicular traffic in 1961, which lasted until 1990. The metropolitan municipality closed the street to vehicular traffic in 1990, reconstructed the tramway and reopened the street for the exclusive use of the pedestrians. Today, Istiklal Street serves as a pedestrian artery to more than 3 million pedestrians daily during the spring and summer months. A rainwater culvert exists underneath the centerline of the street, constructed in 1860 and composed of stone masonry walls and brick masonry vault. In time, the culvert deteriorated due to damage caused by various reasons and caused settlements along the street above, which adversely affected the tramway service and pedestrian movements. Istanbul Second Regional Board for Protection of Cultural Heritage initiated a project in 2011 to restitute the historic culvert by a customized design and construction method that would keep the street fully open to pedestrian traffic and preserve the existing masonry structure of the culvert meanwhile restoring its function as a culvert and improving its water carrying capability. To this end, a customized prefabricated concrete segmental design provided the solution to repair the historic culvert from inside without any major intervention from the street. This paper presents and discusses the customized design and construction method for the restitution of the historic masonry culvert.

Hany El Naggar, Dalhousie University
Alex Campbell, Meco Engineering
Islam Ezzeldin, Dalhousie University

In recent years, two-dimensional finite element modelling has been used to explore how the structural integrity of a corrugated metal pipe (CMP) culvert is affected by simulation of its constituent components (i.e. the pipe metal and/or surrounding soil). However, under various conditions, the nature of the problem is three-dimensional and 2D simulations may fail short to produce reasonable predictions. In this paper, the effect of various loading types on the structural response of round CMP culverts is investigated using three-dimensional (3D) finite element models. The validity of the model was assessed by comparing the model output with previously published results from full-scale laboratory testing. The mechanical behaviour of real soil involves a significant degree of non-linearity. In soil-structure interaction problems such as the one considered here, it seems reasonable to expect that the non-linear behaviour of the soil, together with that of the soil-structure interface, would have a significant effect on the response of the structure. Furthermore, 2D models are limited in their ability to account for certain aspects of the actual, 3D problem. Such aspects include surface live load spreading through the cover soil and the structural behaviour of a corrugated pipe. This paper details the development of a comprehensive, 3D, non-linear FE model capable of simulating the behaviour of intact CMP culverts under backfilling and live loading. Keywords: Culvert, Corrugated Metal Pipe, Finite Element, Soil-Structure Interaction

Michael Katona, Consultant

AASHTO’s Ad Hoc method (AAM) for predicting free-field soil-stress under a rectangular loading area is a simple and very useful tool for the analysis of buried culverts subject to vehicular wheel loads. AAM assumes the surface load spreads with soil depth into an ever-increasing rectangular area whose dimensions are controlled by a constant spread angle θ usually taken as 30o, denoted as AAM-30o. Both simplified and comprehensive culvert analysis procedures routinely utilize AAM soil-stress predictions. To date, a thorough accuracy analysis of AAM-30o has not been published in the open literature. This paper provides a unique and rigorous evaluation of AAM-30o using an exact solution from an elasticity-based model (EBM) of a homogenous half space with rectangular surface load. Key discoveries include a soil-depth parameter called y*, where AAM-30o peak stress exactly matches the exact EBM solution, and a simple formula for y* that only depends on the square-root of the load area. Unfortunately, the accuracy investigation reveals that AAM-30o significantly underestimates peak stress in the shallow depth zone 0 < y < ½y* by as much as 31.3% of the applied surface pressure. Since this a large, nonconservative error it cannot be ignored. Accordingly, a very simple modification is introduced called AAM-θ* where θ* is a spread angle that linearly increases to 30o at soil depth ½y* and thereafter θ* remains constant at 30o. An accuracy evaluation of AAM-θ* reveals an order of magnitude reduction of maximum error, and the small residual error is conservative.

Auchib Reza, Memorial University of Newfoundland
Ashutosh Dhar, Memorial University of Newfoundland

Buried pipeline network forms an indispensable infrastructure that is extensively used for transporting and distributing natural gas and liquid. One of the major problems associated with the performance of this network is related to the deformation of pipelines in areas prone to ground movement. The maximum axial force on the pipeline subjected to axial ground movement is commonly calculated using a design equation developed without proper consideration of soil-pipe interaction. The authors’ recent work revealed that soil-pipe interaction significantly contributes to the axial pullout load, particularly for flexible pipes. This paper presents the results of numerical study conducted to explore the mechanics of soil-pipe interaction that could not be measured during tests. Particularly, the effect of rate-dependent interface behavior of the polyethylene pipe material on pulling resistance could not be measured during the tests. The FE model is developed through validation with full-scale laboratory test results performed at Memorial University of Newfoundland. The study reveals that FE analysis with interface friction angles of 75% to 90% of the peak friction angle of surrounding soil can successfully simulate ground movements of various rates. Based on the results obtained, a simplified equation is proposed to estimate the mobilized frictional lengths for pipeline performance assessment.

Piotr Tomala, ViaCon Sp. z o.o
Michał Mońka, ViaCon Polska
Czesław Machelski, Wroclaw Univerisy

During backfilling of buried structures the deformations are significant and can be controlled using geodetic techniques. Usually the crown point deflection is observed, which is subject to significant changes during the backfilling process. In the initial phase of the construction, due to the lateral pressure of the soil, the shell’s crown point is peaking up and then is reduced by the cover. In this paper the changes of the top radius as a function of vertical displacement of the shell crown were analysed. A characteristic graph is thus created to estimate the safety of the structure both during construction and in the service. The paper presents an algorithm of structure safety assessment based on shell deformation. Construction phase of the structure is analysed. The internal forces in the buried structures are usually several times greater in the construction stage then in the service stage. Results of analyses presented in the paper are therefore significant also as a basis for calculation and behaviour of the soil during the live loads.

Piotr Tomala, ViaCon Sp. z o.o
Maciej Nowak, ViaCon Construction Sp. z o.o.
Czesław Machelski, Wroclaw Univerisy
Meckkey EL SHARNOUBY, Atlantic Industries Limited
Ahmed ALHAMMADI, Ministry of Infrastructure Development
Abd ALRAHMAN ABU AL-RUB, ECO

Steel buried bridges have been an integral part of the North American and European infrastructure for decades. In 2019, the largest steel buried bridge in the world, the Shammal Bridge Crossing, was built for a transportation application in Ras Al Khaimah, UAE utilizing the deepest corrugation 237x500 mm. The structure consist of three low profile arches. Two of them (twins) with span of 32,66 m and a rise of 9,69 m (measured in geometrical axis) which led to a spot on the Guinness World of Records. All of those arches were instrumented with deflection prisms, additionally the one of the record span structures was instrumented in a mid-section with strain gauges. The full-scale test results demonstrated that the performance of the structure is satisfactorily and meets exceeds the targeted demand to capacity ratio.

Jonathan Burton, University of Vermont
Daniel Orfeo, University of Vermont
Steven Stanley, Vermont Agency of Transportation
Michelle Redmond, Vermont Agency of Transportation
Tian Xia, University of Vermont
Dryver Huston, University of Vermont

Proper inspection of small culverts can prevent roadway failures, traffic disturbances, and save tens of thousands of dollars on costly repairs. The Vermont Agency of Transportation (VTrans) has adopted a policy which requires all culverts to be inspected every five years. Because of this, approximately 9,600 small culverts must be inspected annually. In this report, a lightweight inspection vehicle is designed to enable efficient and affordable small culvert inspection. This vehicle is designed, built, and tested to meet a list of requirements generated by the Vermont Agency of Transportation. Optimal settings for video transmission through small culverts are understood through theory and a series of field tests. Vehicle form factor is chosen for maneuverability through small, flooded culverts. Finally, performance for drop inlet inspection scenarios is characterized and discussed.

Piotr Tomala, ViaCon Sp. z o.o
Marcin Szyszka, ViaCon Construction Sp. z o.o.
Piotr Urbański, KGHM S.A

The corrugated steel structure has been installed in a salt mine department of KGHM Company. They rank among the world's best producers of silver and copper. The KGHM runs technologically advanced exploration and smelting activities. Polish copper deposits - one of the biggest in the world - are exploited by three underground mines: "Lubin”, "Polkowice-Sieroszowice” and "Rudna”. The extracted material is enriched in the Concentrator Plant, while the production of copper, silver, gold, lead and other metals takes place in smelters: "Głogów”, "Legnica” and "Cedynia”. The mine is located on the south west part of Poland (lower Silesia voivodeship) near Lubin City. Under the ground on the elevation of 1000m there are the copper ore deposits. Ca. 200 m above it there are a huge salt deposit. Working underground is a hard. Temperature raises to +40C (104F), additionally around there is dry salty air and lot of salt dust. This area must be properly ventilated. Underground corridors from copper mine cross with salt one. Polluted air should not mix with the fresh. Corridors cannot touch each other. In such places, when underground corridors cross itself the ventilation bridges are build. In this paper installation of first grade separation will be described.

Xinbao Yu, University of Texas, Arlington

Corrugated metal pipes (CMP) are subject to corrosion and have a shorter design life as compared to other types of culverts.  Among the several rehabilitation techniques, spray-applied pipe liners (SAPL) are one of the quick ways to rehabilitate deteriorated CMPs. This new method has been less studied with only a few previous laboratory tests and finite element studies. This paper discusses the calibration of 3D full scale FEM model with the test results that were obtained at the CUIRE laboratory at UTA. The laboratory tests were performed on circular invert-cut CMPs that were rehabilitated by polymeric SAPLs. Total of three different thicknesses, 0.25-in., 0.5-in. and 1-in. were used to repair the invert-cut CMPs. The deterioration in the CMP was represented by the removal of 18- in. invert from the intact CMP. A full 3D corrugated model was developed to represent the test setup in the FE model using ABAQUS. The polymeric material used to repair the CMPs were brittle in nature with very small plastic region and it was represented as the simple-elastic plastic material in the FE model. For the calibration process the results from the FE model were compared to the test in terms of load-displacement curves, earth pressure distribution and strain around the liner. The comparison of these parameters showed the discrepancies of less than 10%, thus calibrating the model.  After the calibration process, the FE model was used to generate the load-displacement graphs for other thickness of the liner.