The use of corrugated metal pipes as a soil-structure composite system in either culverts or soil steel composite bridges has become integral to the development of complicated roadways network and/or waterways paths that cope with the current unprecedented continuous urbanization. This paper presents the development of a three-dimensional numerical model of the Enkoping large diameter metal pipe that formed a flexible conduit made of corrugated steel sheets. The developed model considers the effect of representing the soil behaviour around the corrugated sheets utilizing using two commonly used constitutive material models, namely the Mohr-Coulomb (MC) and the Hardening Soil Model (HS), to assess their suitability and effectiveness in simulating the soil behaviour. The analysis compares the recorded field measurements of the internal forces in the Enkoping metal pipe with those numerically calculated. Moreover, the arching actions predicted by the numerical model will be compared to the behaviour of the soil represented by the different soil models.

On examine les déplacements des fines particules qui se produisent dans les fondations des chaussées. On sait depuis plus de 25 ans que les matériaux routiers respectent entre couches les critères de filtre, mais souvent ne respectent pas eux-mêmes les critères d'érosion interne. Bien que cela soit connu, il semble que rien n'ait été fait à ce jour pour corriger la conception des chaussées. Sous le béton bitumineux, des particules plus fines qu'un certain seuil, spécifique au matériau de la couche, peuvent se déplacer dans les pores entre les grains plus grossiers. Les mouvements se produisent sous l'effet des forces dynamiques de traffic, et sous l'effet de l'eau qui s'infiltre par les fissures. Il se forme alors de la ségrégation et des accumulations locales de particules fines. Un matériau, qui avait en moyenne 6% de fines à la pose, peut se transformer en matériau hétérogène qui localement peut avoir de 0% à 30% de particules fines. Les accumulations locales, par une série de mécanismes, font apparaître des nids-de-poule, suite à des cycles de gel et dégel. L'article présente les mécanismes et propose des pistes de solutions pour éviter la création des nids-de-poule et autres désordres locaux, très gênants pour les usagers et très coûteux en entretien et réparations.

Crushed waste rock (CWR) is commonly used for the construction of mining haul roads because of their low cost, high strength, and availability. The resilient modulus is the primary parameter for flexible road design and represent a basic material property that should be used in the mechanistic analyses for predicting different distresses such as rutting and corrugation. Cyclic load triaxial test is the most common method to characterize the resilient behavior (i.e., resilient modulus and permanent deformation) of unbound granular materials (UGM) and soils. However, this method is complex and time consuming, especially considering the short-service-life of mine haul roads. Some correlations between CBR and resilient modulus were proposed for natural coarse soils, but their applicability to CWR remains unclear.
In this study, the geotechnical properties of CWR (particle size distribution, particle density, X-Ray diffraction (XRD), modified Proctor compaction test, CBR, and cyclic load triaxial test) were characterized in the laboratory. A novel test method cyclic load CBR (CL-CBR) test, developed based on standard CBR test, was used to characterize the resilient behavior of CWR. The CL-CBR was further developed to study the stress-dependent behavior of CWR using different shapes and sequences of cyclic axial load. The CL-CBR test results were validated and verified using cyclic load triaxial test results. The existing correlations between CBR and resilient modulus for CWR were verified and modified according to the test results. The effect of moisture content and degree of compaction on the resilient behavior of CWR were also investigated.
The CL-CBR test is a relatively simple and effective method that can provide a good estimate of the resilient behavior of CWR, and can enhance the practical accessibility of characterizing the resilient behavior of CWR. Main results of this study will be presented and discussed in this paper.

The Ministry of Transportation of Ontario (MTO) is considering alternative approach slab configurations to reduce the frequency and severity of pavement surface distress that is commonly observed at the end of approach slabs of bridges. The approach slabs are intended to provide a smooth transition from the embankment to the bridge structure but embankment settlements considerably greater than about 25 millimetres will result in approach slab settlements that impact the highway rideability and, more importantly, can lead to serious safety concerns. As an alternative to the standard approach slab typically used, the MTO is considering a number of approach slab designs ranging from angled slabs to buried slabs, with or without sleeper slabs, and potentially combined with soil or asphalt reinforcement, to reduce the effect of ground settlement on the transition from the approach slab to the bridge deck.

At the Highway 417 over County Road 3 site in Eastern Ontario, the approach slabs (constructed on embankments fills underlain by compressible soils) have experienced poor performance. The settlements at the County Road 3 overpass had been excessive and resulted in significant degradation of the pavement at the approach, which required speed reduction warnings. MTO therefore undertook a study to assess potential approach slab rehabilitation options at that location. The work undertaken included geotechnical investigations and laboratory testing to assess the current soil engineering parameters at the bridge, analysis to estimate the settlements that had occurred (in comparison to surveys of the pavement) and predict the ongoing settlements that might occur. Soil-structure modelling was then carried out to evaluate numerous combinations and permutations of approach slab and pavement configurations to arrive at the most effective design for the rehabilitation of the County Road 3 bridge approaches and to provide guidance for approach slab rehabilitation at other bridges with similar issues.

Constructing new underground tunnels is a necessity in urban areas to resolve the traffic congestion problems in such areas. The new tunnels are passing underneath existing buildings, which might rest on a raft foundation. This study focuses on the effect of the TBM tunnel advancement on the twist behavior of the existing raft foundation. The 3D nature of the TBM construction process has been simulated using PLAXIS 3D software. In order to validate the results of the numerical simulation, the resulted settlement trough has been compared to the measured field settlement trough of a selected case study (Second Heinenoord Tunnel). In the current student, an extensive 3D parametric study is conducted to check the effect of related parameters on the raft twist. The studied parameters include; tunnel cover (Z), raft Inclination (i), raft thickness (d), and raft weight. The results revealed that the raft twist is greatly affected by the tunnel cover (z), the raft inclination (i), and the raft thickness (d). However, the raft weight is not affecting the raft twist behavior.

As part of the seismic rehabilitation assessment of the Jacques Cartier bridge in Montréal-Longueuil, Québec, a detailed geotechnical investigation was carried out. The bridge represents a lifeline bridge as defined in CAN/CSA-S6-14 and is an important transportation link over between the Island of Montreal and the South Shore of the St Lawrence with a total span of 3km.

The bridge is supported on a range of different foundation types, including large piers supported directly on bedrock, large piers supported on over 140 wood piles, small piers supported directly on soils and small piers supported directly on wood piles. The bridge is supported on 55 piers and 2 abutments covering range of spans from about 30 m to 332 m, and includes a plaza structure within its overall length. The ground conditions cover a wide range of bedrock types, from breccia intrusions to shale sedimentary rock, and soils ranging from silty clay to loose sands to dense glacial tills. Deep fills were also present in several locations.

The field investigation included boreholes, downhole geophysics and cone penetration tests (CPTs). A series of test pits were also excavated on the Montreal shore to expose and assess some of the wood piles dating back to the 1930s.

The results of the field investigation were used to assess site response relative to seismic loading, the potential for seismic liquefaction, and to model the dynamic axial and lateral load capacity/stiffness of the foundations. This case study reveals several interesting aspects relative to the seismic performance of the structure from the potential for seismic liquefaction, the dynamic response of specific sections of the bridge to seismic loads, the lateral dynamic stiffness and capacity of the existing foundation systems. Recommendations for additional field investigations as part of the next phase of bridge assessment were also provided.