Assessment of Climatic and Anthropogenic Controls on Bridge Deck Drainage and Sediment Removal

Bridge deck drainage is essential to prevent hydroplaning and maintain safety along major roadways. With projected changes in climate, current designs may not be sufficient and a better understanding of the primary controls (climate, bridge deck, and inlet design) on the hydraulic efficiency and sediment removal of drainage systems is needed to maintain public safety. To evaluate the controls on hydraulic drainage efficiency, 576 controlled laboratory experiments were conducted testing grate type (rectangular bar vs. curved vane) and downspout configuration (square vs. circular and 20 cm vs. 25 cm) across a range of flow rates, cross slopes, and longitudinal slopes. An additional 144 sediment erosion experiments were performed to identify controls on the removal of sediment. Hydraulic testing indicated that inflow driven by climate is a primary control on drainage efficiency and spread of water on a roadway. For anthropogenic controls, downspout opening size was found to be the primary control followed by longitudinal slope. Sediment removal results indicated that inflow regime and grate type were the primary controls on the sediment removal rate. Given that inflow, driven by climate, is a control on both hydraulic and sediment removal performance, hydraulic engineers should consider forecasted changes in rainfall intensity in their present-day drainage designs. We provide design guidance and discussion for developing a proactive approach to hydraulic infrastructure in the face of future climate uncertainty.

Incipient motion of Armorflex articulating concrete blocks on steep slopes

Armorflex is an articulating concrete block erosion protection measure that has been used as an alternative to riprap for many years. Even though extensive research and hydraulic testing have been conducted on Armorflex, the principal constraint on the use of concrete blocks has been the lack of information on prototype performance. Furthermore, there are no standards for Armorflex or articulating concrete block revetments in the South African National Standards, and design guidelines from Armorflex manufacturers are insufficient. The aim of this study was to improve the understanding of the critical flow conditions under which Armorflex blocks are lifted and removed by flowing water in open channel flow applications. Scaled laboratory tests were conducted on Armorflex 140 and Armorflex 180 blocks. Liu's theory of 1957 is applied in an attempt to define the point where block movement is initiated.

Induced Bank Filtration: Hydraulic Testing of Pilot Filters

Hydraulic tests were performed on two pilot scale filters as part of a water treatment project in the village of Nersa, Karnataka, India. The filters use locally sourced alluvial material to filter E.coli contamination using natural processes that mimic those in Riverbank Filtration (RBF). Two pilot scale filters were tested, one containing locally sourced granular activated carbon (GAC) and one without. A falling head test and tracer test were preformed, and breakthrough curves were used to analyze the hydraulic performance. E.coli data were also collected, and percent removal was calculated to determine the effectiveness of the filters. Relative to the influent water, the E.coli removal percentage of Filter 1 (no GAC) was consistently high and ranged between 97.1% and 100% E.coli. The addition of GAC did not improve performance in this study. Overall, the effectiveness in bacteria removal observed in the non GAC filter warranted construction of a full-scale system.

Localization of Plastic Deformation in Ti-6Al-4V Alloy

This article investigated the mechanical behavior of Ti-6Al-4V alloy (VT6, an analog to Ti Grade 5) in the range of strain rates from 0.1 to 103 s−1. Tensile tests with various notch geometries were performed using the Instron VHS 40/50-20 servo hydraulic testing machine. The Digital Image Correlation (DIC) analysis was employed to investigate the local strain fields in the gauge section of the specimen. The Keyence VHX-600D digital microscope was used to characterize full-scale fracture surfaces in terms of fractal dimension. At high strain rates, the analysis of the local strain fields revealed the presence of stationary localized shear bands at the initial stages of strain hardening. The magnitude of plastic strain within the localization bands was significantly higher than those averaged over the gauge section. It was found that the ultimate strain to fracture in the zone of strain localization tended to increase with the strain rate. At the same time, the Ti-6Al-4V alloy demonstrated a tendency to embrittlement at high stress triaxialities.

Effects of residual stresses on the bending stiffness of shafts strengthened by enveloping de-formation

The aim was to study the effects of technological residual stresses on the bending stiffness of cylindrical parts of shafts and axes. Experiments were conducted for elongated cylindrical specimens made of steel grade 35 with a diameter of 30 mm using boring and turning methods. Specimens were annealed in a protective medium to remove initial residual stresses. Experiments were carried out using an Amsler laboratory hydraulic testing machine and VK8 grade hard-alloy matrices. The experiments showed that, for an extremely low degree of relative crimping of 0.1 to 0.5%, the size of the layer with tangential residual compression stresses gradually decreases. The stiffness of such cylindrical workpieces remains almost unchanged. An increase in relative crimping (from 0.5 to 1.2%) leads to a decrease in resi dual compression stresses on the part surface. The layer thickness with tangential residual compression stresses starts to increase. This leads to a decreased residual buckling and an increased bending stiffness. It was found that the degree of relative crimping has no effect on the variation of distribution depth of axial residual stresses. Optimal distribution of tangential residual compression stresses can be reached by increasing their depth. A linear relationship was found for relative crimping of 0.1 to 1.0%. The highest bending resistance was recorded for specimens strengthened by residual crimping of about 1.0%. By processing workpieces using enveloping deformation with crimping of 0.1% and loading them with a transverse force of 0.6 kN, bending distortion can be decreased and the strength of parts can be increased by 5 times. It was found that the bending stiffness of cylindrical shafts is greatly affected by residual compression stresses. The bedding depth of residual stresses has various effects on the stiffness of cylindrical parts. Thus, correct use of strengthening enveloping deformation can form a high-quality surface layer on parts with the pre-defined distribution of residual stresses.

Importance of fracture deformation throughout hydraulic testing under in-situ conditions

Summary In this work, we propose a hydro-mechanical simulation model to study the strong interaction of fluid flow and fracture deformation under in-situ stress conditions. The general model is reduced under physics-based assumptions to provide an efficient numerical approach for inverse analysis of experimental studies and is applied to experimental field data obtained from hydraulic tests conducted at the Grimsel Test Site (GTS), Switzerland. The present set of hydro-mechanical measurement data provides not only valuable information about the transient pressure and flow evolution but also the transient change of fracture deformation. We aim to introduce a strongly-coupled hydro-mechanical model to numerically characterize the fractured reservoir based on experimental data below the limit of hydraulically induced irreversible changes of the reservoir’s properties. Insights into the leading mechanisms of flow processes throughout hydraulic testing under in-situ conditions are then gained by best numerical fits of the measurement data. Based on the experimental and numerical findings, this study emphasizes the importance of a consistent consideration of local and non-local fracture deformation throughout inverse analysis of hydraulic testing data to a) better understand hydro-mechanical flow processes in fractured reservoirs and b), to increase the estimation quality of hydraulic properties of tested fractures.

Downhole Annular Barrier Solution for Sustained Casing Pressure - Trinidad Case Study

Objectives/Scope Downhole Annular Barrier (DAB) systems employed in intervention can correct integrity and conformance control issues during well lifecycle, extending the productive term in a safe and costeffective manner. These emergent wireline technologies come with unique challenges for logistics, quality control, and engineering, but can also provide solutions to difficult problems, with high value to spend ratio, in the non-rig intervention sector. The paper will review one such successful intervention, completed offshore Trinidad W.I., in a gas well presenting long term Sustained Casing Pressure (SCP). The desired end state of the well was A-Annulus at 0 psi SCP, which would return the well to a safe state and permit a planned infrastructure project to move ahead. Methods, Procedures, Process Operational objective was isolation of the casing annulus pressure from the source by injecting epoxy into the annular space at depth, forming a 360-degree pressure barrier. The project can be broken down into three main sections. The paper and presentation will address each section with its specific challenges, learnings, and outcomes: Onshore Epoxy and Tool Preparation Each Downhole Annular Barrier job employs a custom recipe epoxy suited to the planned logistics timing and expected bottomhole conditions. Quality control of the epoxy recipe and mixing process as well as temperature control of the batch after mixing is key to the sealing properties of the final epoxy plug. • An Epoxy Lab and Mixing Station was dismantled, air freighted, and reconstituted in Trinidad near to the field operations port. Special insulated offshore CCU were built to transport and contain filled epoxy canisters while maintaining low temperature requirements (near to 0 deg C for up to 30 days). • Build and System Integration Testing (SIT) of the downhole system (anchoring, stroking, hydraulic testing, perforation, and injection) with the electric line system (conveyance, telemetry, power). Offshore Job Execution The DAB system employed is designed to complete multiple operations in a single trip into the well, including perforating and high-pressure epoxy injection, with precise position control and monitoring. This is made possible with the multi-function modular tool. The operation was dynamic by design and contingencies were implemented based on the well response. Multiple epoxy annular plugs were placed into the A Annulus at depth, with high pressure injection. Results, Observations, Conclusions Well Response and Assessment Utilizing advanced annular surface monitoring technology and PvT analysis, precise assessment of the annulus pressure build was recorded throughout the operation. Once the project criteria were met, the operation was successfully concluded.

Effects of Polyethylene Ground Plastic Waste Aggregate for Concrete Mixing Proportion

In recent times, the production of polyethylene ground plastics has increased markedly in the Philippines. However, current levels of their usage and disposal generate several environmental problems. Recycling is one of the most important actions that are being made to reduce these impacts. The present study used polyethylene ground plastic wastes to investigate their possible use as plastic aggregate in concrete application. The shredded plastic wastes were used in concrete with partial replacement of ½ kg and 1kg by volume of conventional coarse aggregate. Three types of concrete specimens including one without plastic aggregate were used in the study for comparison. All the concrete specimens were tested for their different mechanical properties after a curing period of 28 days. Various physical properties of all aggregates and fresh concrete properties were also tested in the laboratory, these include pound per square inch (psi), Mega Pascal (MPa), Kilo Newton (KN), and the type of fracture. The test for psi, MPa, and kN resulted that concrete mixtures with 1kg ground plastic produced the best result among the three samples having 3150 Psi, 21.7 MPa, and 395.7 KN, respectively. Moreover, the specimens were loaded under a monotonic uniaxial compressive load up to failure by using MATEST hydraulic testing machine with the indicator of kN. The result showed that both standard mixtures of concrete and the standard mixture of concrete with ½ kg polyethylene ground plastic have a comparison infraction that has a result of an SW-Shear Wedge of Type 5, while the standard mixture of concrete with 1kg polyethylene ground plastic has a conical type of a fracture. Based on the several tests conducted, it is concluded that the standard concrete mixture with 1kg polyethylene ground plastic provided the best result compared to other specimens. Furthermore, the use of polyethylene ground plastic waste in the standard concrete mixture provides some advantages like on reduction of plastic wastes, prevention of environmental pollution, and energy saving.

Numerical simulation of the movement behavior of floating structures

The sea level is rising, and floods threaten the infrastructure all over the world; therefore, we should identify the risks for envelops of buildings and settlements. The risks arise due to the new boundary conditions and a direct contact between the water flows in motion. A floating construction site requires a manifold adaptation of structures. The paper demonstrates the effect of water waves on floating houses built on abandoned open pit mines. Pictures of destroyed accessways to such properties have proven the need to study the effect of water waves on floating houses. In order to minimize the time and spending on experimental activities, some of the field studies should be replaced by numerical simulations using modern computing equipment and ANSYS FLUENT, ANSYS MECHANICAL FSI, and ANSYS AQWA software. The results can be validated using a hydraulic testing channel (15 x 5 m), a floating platform near the harbor of Lake Gro r schener See and floating houses in the Lusatian Lakeland. The results demonstrate the wave forces acting on the structures of the pontoons. New connection elements, adapted versions of materials and structures have been developed, water waves are damped, and options for the wave energy use have been analyzed.