Floating road construction on soft soil

The main problem of road construction on saturated soft soils is due to their low bearing capacity and large settlement. One of the solutions to such problems is to install piled box culverts-geofoam. In this study, the pile box culvert-geofoam was modelled as raft foundation. This experimental study was conducted by making a prototype raft file foundation gradually loaded with a maximum vertical load of 20 kN. Different thicknesses of geofoam were utilized in order to observe the influence of thickness on the settlement. Furthermore, difference in settlement is also found when the culvert was constructed with and without geofoam. Thicker geofoam was observed to result in smaller settlement.

Numerical simulation of box culverts subjected to different physical actions and design regulations

This research work was intended to provide a broad and suffcient solution to areas of diffcult vehicular traffic, where during the rainy season some watersheds present a non negligible water flow. The research carried out the structural design of different geometries of box culverts, to provide a solution to vehicular continuity in areas affected by water ows that interrupt pedestrian and vehicle traffic, endangering human lives. The structural designs followed the standards established by the American Association of State Highway and Transportation Offcials and the Colombian bridge code. The designs were carried out using commercial software SAP2000 for analysis and design through Visual Basic programming, allowing a wide range of geometries and boundary conditions to be established. The structural designs indicated a significant difference in quantities of work in the construction of the box culverts for different geometries, indicating higher volumes of concrete for the designs made using the American Association of State Highway and Transportation Offcials code compared to Colombian bridge code. The Colombian bridge code has higher steel requirements for fills less than 3.00 m, while for greater heights the American Association of State Highway and Transportation Offcials code has the highest steel requirements.

A parametric design process model for box culverts

This research proposes a parametric design process model to improve the structural engineering project team performance by automating the design and three-dimensional modelling procedures of box culverts. Although standardised design procedures can reduce the design time of repetitive structures such as box culverts, the increased time and effort required for revising construction drawings negatively impacts a project's performance. A literature review was conducted to develop a theoretical process model to improve the current structural design optimisation and three-dimensional modelling procedures of box culverts. The proposed process model was validated using structured interviews with professionally registered structural engineers for appropriateness to box culverts and the potential to improve project performance. The data analysis revealed that the interviewed engineers were in favour of automating the design optimisation and three-dimensional modelling procedures of box culverts. Moreover, parametric design automation would result in improved project performance when encountering an inevitable design change. However, the user's control over the output of each process should not be discarded. This study can help readers understand the transformation of the structural design and three-dimensional modelling procedures of repetitive structures, such as box culverts, into an algorithmic form to achieve improved project performance.

Comparative Analysis of Two cell and Three cell Box Culvert for Different Aspect Ratio

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.

Probabilistic Moment Capacity Models of Reinforced Concrete Slab Members for Underground Box Culverts

This study was performed to evaluate the probabilistic characteristics of the flexural strength of reinforced concrete (RC) flexural members adopted for underground box culverts. These probabilistic models were developed to be adopted for the development of limit state load combination formats for underground RC box culverts. The probabilistic models of uncertainties inherent in the basic design variables were developed to evaluate flexural strength using field material test data as well as field survey data collected from various domestic construction sites of underground box culverts in Korea. The basic design variables include concrete strength, steel rebar strength, and section dimensions, such as slab thickness and rebar locations. Some design variables are assumed to have inherent construction error characteristics, which may be different from those inherent in the RC members for buildings and bridges. The bias models on flexural strength were evaluated based on the experimental results of four-point flexural tests on one-way RC slabs, which were fabricated following the general practice adopted in the local underground box culvert construction process. Based on the probabilistic models of basic design variables, as well as the bias models of flexural strength, Monte Carlo simulations were performed to examine the probabilistic characteristics of both ultimate flexural strength and yield moment strength of RC slab members. Some sensitivity analyses were performed to confirm the soundness of various probability models and the assumptions adopted in the development procedure. The proposed procedure may be applied to develop probabilistic resistance models for structural members, in which the construction error characteristics are assumed to be different from other practices.

Damage Identification of Prefabricated Reinforced Concrete Box Culvert Based on Improved Fuzzy Clustering Algorithm and Acoustic Emission Parameters

Prefabricated box culvert is a new structure in road engineering, whose health is very important to road safety. The use of acoustic emission (AE) as a detection method and the use of other improved algorithms to evaluate the damage of prefabricated box culverts are still insufficient. In this paper, two kinds of prefabricated box culverts are tested and studied, and the damage process of the box culverts is analysed based on the AE parameters of the box culvert using the traditional fuzzy C-means method (FCM). In addition, an improved algorithm based on the combination of grid density and distance (G-DFCM) was proposed, which was simulated and applied to the AE data analysis of the prefabricated box culvert. The research results show that the application effect of the G-DFCM algorithm is good, which not only overcomes the shortcomings of the original algorithm but also improves the effectiveness of the algorithm. This work can provide a supplement to the damage identification of fabricated box culverts.

Use of a combined drainage/fauna underpass by the Spotted-tailed Quoll, Dasyurus maculatus

ABSTRACT Combined drainage/fauna culverts and dedicated fauna underpasses are routinely used to mitigate the potential barrier effects of roads and reduce road-related mortality. To determine the success of underpasses constructed as part the Pacific Highway Upgrade in eastern NSW automated cameras were used to monitor a number of underpasses. The first monitoring period (autumn 2018) recorded photographic evidence of a Spotted-tailed Quoll Dasyurus maculatus using a combined underpass on day 61 of a 63-night monitoring period. To our knowledge, this is the first photographic evidence of use of an underpass by a D. maculatus in NSW and supports the installation of box culverts as a mitigation measure to facilitate movement for this species.