scholarly journals Post-construction performance of induced trench rigid culverts

2016 ◽  
Vol 53 (11) ◽  
pp. 1807-1821 ◽  
Author(s):  
Benjamin L. McGuigan ◽  
Olajide Samuel Oshati ◽  
Bethanie A. Parker ◽  
Arun J. Valsangkar

Induced trench construction is commonly used to reduce earth pressures on rigid circular and box culverts. Most of the reported literature pertains to the performance of induced trench culverts during construction and shortly after construction. This paper addresses the post-construction performance of induced trench culverts. First, results of field inspection reports are presented as an indirect assessment of performance of 90 induced trench culverts installed in New Brunswick that have been in service for up to 24 years. Second, earth pressure measurements are presented from three case studies where prototype installations were monitored over periods ranging from 4 to 9 years. The case studies presented include a single circular culvert, a cast-in-place double-cell box culvert, and a twin circular culvert installation. The fill heights above the instrumented structures varied from 19 to 25 m. All the available data from both the field inspections and earth pressure measurements indicate that the culverts installed in induced trenches are performing in a satisfactory manner.

2010 ◽  
Vol 47 (2) ◽  
pp. 147-163 ◽  
Author(s):  
Benjamin L. McGuigan ◽  
Arun J. Valsangkar

Induced trench construction is routinely used for circular conduits, but its application for box culverts is less common. To understand the complex soil–structure interaction issues related to the design of induced trench box culverts, centrifuge tests were performed to measure earth pressures on a model box culvert installed in several induced trench configurations. These tests were modelled with FLAC and good agreement was achieved. A parametric study performed with FLAC identified a preferred compressible zone geometry having a width of 1.2 times the culvert width and a thickness of 0.5 times the culvert height. For this geometry, the earth pressure on the top was 0.28 times the overburden, the lateral earth pressure on the sides was 0.47 times the mid-height overburden, and the contact pressure at the base was 0.73 times the overburden plus the pressure from the dead load of the culvert. The average base contact pressures for the induced trench geometry were 35% lower than those for the corresponding positive projecting case. The induced trench method, therefore, appears to be a viable option for box culverts installed under high embankments.


2012 ◽  
Vol 49 (11) ◽  
pp. 1267-1284 ◽  
Author(s):  
Olajide Samuel Oshati ◽  
Arun J. Valsangkar ◽  
Allison B. Schriver

Earth pressure data from the field instrumentation of a cast-in-place reinforced rectangular box culvert are presented in this paper. The instrumented culvert is a 2.60 m by 3.60 m double-cell reinforced cast-in-place rectangular box buried under 25.10 m of fill constructed using the induced trench installation (ITI) method. The average earth pressure measured across the roof was 0.42 times the overburden pressure, and an average of 0.52 times the overburden pressure was measured at mid-height of the culvert on the sidewalls. Base contact pressure under the rectangular box culvert was also measured, providing field-based data demonstrating increased base pressure resulting from downward drag forces developed along the sidewalls of the box culvert. An average increase of 25% from the measured vertical earth pressures on the roof plus the culvert dead load (DL) pressure was calculated at the culvert base. A model culvert was also tested in a geotechnical centrifuge to obtain data on earth pressures at the top, sides, and base of the culvert. The data from the centrifuge testing were compared with the prototype structure, and the centrifuge test results agreed closely with the measured field prototype pressures, in spite of the fact that full similitude was not attempted in centrifuge testing.


2008 ◽  
Vol 45 (1) ◽  
pp. 85-101 ◽  
Author(s):  
Rodney P. McAffee ◽  
Arun J. Valsangkar

The field performance of an induced trench installation is compared to the results of centrifuge testing and numerical modelling. The measured vertical pressure at the crown of the pipe in the field ranged from 0.24 to 0.36 times the overburden pressure. The horizontal earth pressures measured in the field at the springline level determined a coefficient of lateral earth pressure between 0.39 and 0.49. The culvert was monitored over a period of 2 years following completion of embankment construction indicating no measurable changes in earth pressures and deformations. A model box culvert simulating the prototype height of soil cover, the pipe width, and the thickness of the compressible layer was tested using a geotechnical centrifuge. The prototype structure was also evaluated using numerical modelling to predict full earth pressure distribution and deformations. A comparison of field data, centrifuge testing, and numerical modelling shows that the Marston–Spangler theory used in designing induced trench culverts is conservative. The theory however, does not address or predict the nonuniform pressures on the top, sides, or bottom of the pipe, and therefore numerical analysis should be used to estimate the complete pressure distribution.


Author(s):  
Osama Hussien

Culverts are often required under earth embankment to allow for the crossing of a watercourse, like streams, to prevent the road embankment from obstructing the natural waterway. The opening of the culvert is determined based on the waterway required to accommodate the design flood, whereas the thickness of the culvert section is designed based on the loads applied to the culvert. This paper studies some design parameters of box culverts, such as the thickness of the haunch, the coefficient of earth pressure, the thickness of box culvert, and depth of fill on the top slab, to show the effect of haunch on the stresses of the box culvert. The study investigated the variation in stresses and the cost comparison made for different width of the box culvert. The percentage reduction in the cost of culvert based on the presence of haunch is presented.


2020 ◽  
Vol 870 ◽  
pp. 11-19
Author(s):  
Layth Abdul Rasool Al Asadi ◽  
Hussein Shakir Al Bahrani ◽  
Luay Kadhim Al Waeli

Box culverts are the monolithic unit build to pass across railway lines, roadways, etc. earthworks are made to balance the discharge water on both sides. Box takes different types of loads created by a cushion, traffic, water, soil, etc. This paper deals with the optimum design of box culvert by using Newton's-Raphson Method and AppDesigner in MATLAB Software R2017a and studies the design parameters such as the influence of depth of earth fill at the top slab of the culvert, earth pressure, factor Dead Load, Live load, effective width, etc. In this paper, the study of the box-culvert with normal and minimum cushion analyzed for different classes of loadings and conclusions made on the basis of Newton's-Raphson Method normal and minimum cushion and normal cushioning cases.


Author(s):  
Gaurav Shrivastava

Abstract: Culverts serves primarily as the hydraulic conduits conveying water from one side of a roadway or similar traffic embankment to the other; therefore, culverts serves the dual purposes of functioning as hydraulic structures as well as acting as traffic load bearing structures. They are normally cheaper than bridges, which make them the natural stream passes through channels. Box culvert are most stable and safe among various types of culverts. It can be constructed for soft soil conditions also. Therefore these are the best alternative to the major bridges for the small span and for cross drainage situation. In this work, we analyze the R.C. box culvert of two cell and three cell with different L/H ratio with the use of STAAD Pro software. In this study, we consider the span of culvert bridge as 10 m and we done the analysis for two cell and three cell culvert on the same span and varies the height with respect to span of the culvert bridge for different aspect ratio. Here we considered the traffic loading of Class AA loading as per IRC:6 2014 and also consider all the loading conditions as per IS codes. The structure designing includes the considerations of pressure cases (Box empty, Full, surcharge load) and factors such as Impact load, Braking force, Dispersal of load through fill, Effective width, Coefficients of earth pressure, Live load etc. The analysis of structure as per limit state method IS 800-2007. The IS standard requirements in the design manual for roads and bridges (IRC6-2014, IS 112-2011) is used in the structural designing of concrete box culverts. The structural elements of two cell and three cell Box culverts are compared with respect to its maximum moments respectively for the different L/H ratio on the same span of the culvert. In the results we conclude that the moments are less than the two cell Box culvert with comparison to three cell Box culvert for the constant span of both the cases of culverts. In the present study, this paper provides full discussion on the provisions in the codes, considerations and justifications of all the above aspects of design. Keyword: Box culvert, aspect ratio, Staad pro, IRC codes.


1981 ◽  
Vol 18 (4) ◽  
pp. 566-572 ◽  
Author(s):  
N. R. Morgenstern ◽  
D. C. Sego

The construction of an underpass in the City of Edmonton required the temporary relocation of the CNR main-line prior to the construction of a permanent bridge. The line was placed close to the underpass excavation which was supported by a tie-back sheet pile wall. Because of the stringent requirements associated with the presence of the railway line, the supports were designed on a conservative basis and observations of tie-back loads were taken over a period of 7 months.This note presents the observations of tie-back loads from January to July, 1977. Following installation in accordance with the design requirements, substantial fluctuations in tie-back load were observed for about 3 months. Then the loads fell off gradually to about 50% of the originally applied values. The variation of the load with time bears a strong correlation with average air temperature and is accounted for by the alternate freezing and thawing of the ground adjacent to the sheet pile wall. The ultimate decline in load is attributed to relaxation of the soil behind the wall during spring thaw. The case history draws attention to special requirements associated with interpretation of earth pressure measurements during winter con struction.


Author(s):  
Bethanie A. Parker ◽  
Rodney P. McAffee ◽  
Arun J. Valsangkar

An induced trench installation was instrumented to monitor earth pressures and settlements during construction. Some of the unique features of this case study are as follows: (a) both contact and earth pressure cells were used; (b) part of the culvert is under a new embankment and part was installed in a wide trench within an existing embankment; (c) a large stockpile was temporarily placed over the induced trench; and (d) the compressible material was placed in two stages. The maximum vertical pressure measured in the field at the crown of the culvert was 0.24 times the overburden pressure. The maximum horizontal pressure measured on the side of the culvert at the springline was 0.45 times the overburden pressure. The column of soil directly above the compressible zone settled approximately 40% more than did the adjacent fill. The field results at the crown and springline compared reasonably with those observed with numerical modeling. However, the overall pressure distribution on the pipe was expected to be nonuniform, the average vertical pressure calculated by using numerical analysis on top of the culvert over its full width was 0.61 times the overburden pressure, and the average horizontal pressure calculated on the side of the culvert over its full height was 0.44 times the overburden pressure. When the full pressure distribution on the pipe is considered, the recommended design loads from the Marston–Spangler theory slightly underpredict the maximum loads, and the vertical loads control the design.


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