Improved Surface Loading Stress Analysis Method Considering Protection Measures

2020 ◽  
Author(s):  
Shenwei Zhang ◽  
Ken Zhang ◽  
Maria Pino ◽  
Jonathan Law ◽  
Tammie Matchim
Keyword(s):  
Cost Effective ◽  
Effective Length ◽  
Live Load ◽  
Surface Loading ◽  
Protection Measures ◽  
Surface Protection ◽  
Vehicle Loading ◽  
Good Consistency ◽  
Mat Thickness ◽  
Modified Equation

Abstract This paper presents a methodology to evaluate pipe stress induced by surface vehicle loading at uncased road crossings that are protected by mat or bridging. When vehicles cross an existing pipeline, additional circumferential and longitudinal pipe stresses induced by surface vehicle loadings should be comprehensively considered to ensure pipe integrity and safe operation. Surface protection measures are sometimes installed to distribute the surface loading away from pipe centerline and reduce “footprint pressure”. A modified CEPA equation was proposed to calculate the radius of relative stiffness (or effective length) of mat and was validated by comparing with results from continuum FEA. The effective length calculated by the modified equation demonstrates good consistency with the FEA-predicted effective length. An approach was proposed to evaluate the pipe stress with user-defined free span of bridging, which provide flexibility for optimizing bridging protection in the field. A tool was developed to facilitate the assessment of surface loading stress of pipeline with mat or bridging protection. Case studies were presented to demonstrate the application of the proposed methods and the effect of mat thickness or bridging free span on the reduction of live load stress. The proposed methods will benefit pipeline operators with derived cost-effective protection measures for vehicle crossing while assuring safety of pipeline operation.

scholarly journals Enhancing the Ecological Value of Sea Dikes

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1617 ◽  
Author(s):  
Scheres ◽  
Schüttrumpf
Keyword(s):  
Climate Change ◽  
Climate Change Adaptation ◽  
Interdisciplinary Collaboration ◽  
Ecological Value ◽  
Protection Measures ◽  
Surface Protection ◽  
Societal Needs ◽  
Ecological Aspects ◽  
The World ◽  
Sea Dikes

Sea dikes protect low-lying hinterlands along many coasts all around the world. Commonly, they are designed as embankments with grass covers or grey revetments accounting for the prevailing hydraulic loads. So far, incorporation of ecological aspects in the dike design is limited. With regard to increasing environmental awareness and climate change adaptation needs, the present study reviews methods for ecological enhancement of sea dikes and discusses limitations and challenges related to these methods. In doing so, one key aspect is to maintain dike safety while increasing the ecological value. Potential for ecological enhancement of sea dikes has been found regarding natural or nature-based solutions in the foreshore, dike surface protection measures (vegetated dike covers, hard revetments and dike roads) and the dike geometry. While natural and nature-based solutions in the foreland are investigated thoroughly, so far only few experiences with ecological enhancements of the dike structure itself were gained resulting in uncertainties and knowledge gaps concerning the implementation and efficiency. Additional to technical uncertainties, engineers and ecologists meet the challenge of interdisciplinary collaboration under consideration of societal needs and expectations.

Improved Surface Loading Stress Analysis Method Considering Protection Measures

2021 ◽  
Author(s):  
Shenwei Zhang ◽  
Ken Zhang ◽  
Maria Pino ◽  
Tammie Matchim ◽  
Jonathan Law
Keyword(s):  
Stress Analysis ◽  
Analysis Method ◽  
Surface Loading ◽  
Protection Measures

Sustainable and environmentally friendly zinc coatings for protecting steel bridges in Europe

2021 ◽  
Author(s):  
M. C. van Leeuwen ◽  
P. M. Gangé ◽  
B. Duran ◽  
F. Prenger
Keyword(s):  
Corrosion Protection ◽  
Life Cycle Cost ◽  
Zinc Coating ◽  
Environmentally Friendly ◽  
Cost Effective ◽  
Steel Bridges ◽  
Metallic Zinc ◽  
Protection Measures ◽  
Paint Systems ◽  
Zinc Coatings

<p>Metallic zinc coatings are well established as cost-effective corrosion protection for steel bridges. The zinc coating acts first as barrier protection, isolating the base steel from corrosive elements, and secondly by cathodic protection, acting as a sacrificial anode to protect the steel should the coating be compromised. Bridge operators can be confronted by disproportional high maintenance costs for bridges in use as removal of (in)organic paint systems with hazardous and toxic compounds require expensive waste disposal and environmental protection measures. Metallic zinc coatings are recognized as environmentally friendly, sustainable, and low maintenance, providing the lowest life cycle cost corrosion protection. Various case studies with bridges protected with metallic zinc coatings in and outside Europe are illustrated.</p>

High Temperature Sliding of TiC Based Hardmetal Coatings Against TWIP Steel

2021 ◽  
Author(s):  
M. Varga ◽  
L. Janka ◽  
M. Rodríguez Ripoll ◽  
L.-M. Berger ◽  
S. Thiele ◽  
...  
Keyword(s):  
Twip Steel ◽  
Cost Effective ◽  
Wear Loss ◽  
Feedstock Powder ◽  
Surface Protection ◽  
Spray Coatings ◽  
Spray Process ◽  
Pin On Disc ◽  
Steel Grades ◽  
Corrosive Environments

Abstract Manufacturing of steel components is often done at high temperatures (HT) posing a serious challenge to components such as forming tools. Thermal spray coatings provide a cost-effective solution for surface protection under HT, corrosive environments and severe wear conditions. Thermally sprayed coatings based on cubic hard materials such as TiC and TiCN can provide an alternative to widely used Cr3C2-NiCr. While the latter possess a superb oxidation resistance and wear resistance at HT, they are prone to degradation in the presence of Mn, an element commonly alloyed in many modern steel grades such as TWIP (twinning-induced plasticity steel). In this study, a (Ti,Mo)(C,N)-29% Ni hardmetal feedstock powder was prepared by agglomeration and sintering. Coatings were deposited using a high velocity air-fuel (HVAF) spray process. The coating was benchmarked against a standard Cr3C2-NiCr coating obtained with the same spray process. Our work comprises analyses of the feedstock powder along with the resulting coating microstructure after deposition and heat treatment. Further, the HT sliding behavior against TWIP steel using a HT pin-on-disc tribometer at 700°C was investigated. The results showed a clear benefit of the TiCN-based coating, with almost no wear detected, while the Cr3C2-coating showed a significant wear loss. Based on these results, the TiCN-based coating is regarded as potential solution for prospective forming applications of modern high Mn steels, such as TWIP.

scholarly journals An improved transmitter system to accurately measure wet-bulb temperature of air

2019 ◽  
Vol 52 (7-8) ◽  
pp. 1002-1007
Author(s):  
Liangwen Yan ◽  
Peng Yu ◽  
Sijung Hu ◽  
Qiu Gao ◽  
Wei Li ◽  
...  
Keyword(s):  
Real Time ◽  
Latent Heat ◽  
Measurement Accuracy ◽  
Cost Effective ◽  
Mean Value ◽  
Experimental Results ◽  
Iteration Algorithm ◽  
Good Consistency ◽  
The Mean ◽  
Good Agreement

A cost-effective measurement of wet-bulb temperature of air has great benefits to fulfill a growing demand of industry, cultivation agriculture, and medication. Applying an appropriate algorithm to wet-bulb temperature of air measurement can effectively improve the accuracy and speed of its measurement. The study aims to research how an improved transmitter system along with the latent heat–based iteration algorithm is used to precisely measure wet-bulb temperature of air. The work consists of (1) simulation of the iteration algorithm and (2) validation via experimental protocol. The simulation results through latent heat–based iteration algorithm were in good agreement ( R2≥ 0.99) with the reference. The performance of the improved wet-bulb temperature of air transmitter system was tested by a latent heat–based iteration algorithm experimental setup. The experimental results demonstrate that the improved wet-bulb temperature of air in a good consistency with commercial wet-bulb temperature of air in a range of temperature (15°C–34°C) and relative humidity (28.8%–76.2%). The Bland–Altman plot also shows that the mean value and the standard deviation of the differences between these two systems are 0.14°C and 0.29°C, respectively, which indicates that the improved wet-bulb temperature of air has a good agreement as well. Compared with the commercial wet-bulb temperature of air transmitter system, an advanced processor (STM32F103C8T6) and real-time operating system was applied in the improved wet-bulb temperature of air transmitter system. The experimental results show that its measurement accuracy is closer to the previous study. This study provides an alternative and cost-effective solution to accurately and real-time measure wet-bulb temperature of air.

scholarly journals Persistent effects of sand extraction on habitats and associated benthic communities in the German Bight

2020 ◽  
Author(s):  
Finn Mielck ◽  
Rune Michaelis ◽  
H. Christian Hass ◽  
Sarah Hertel ◽  
Caroline Ganal ◽  
...  
Keyword(s):  
Benthic Communities ◽  
Effective Means ◽  
Local Population ◽  
Benthic Fauna ◽  
Cost Effective ◽  
Habitat Characteristics ◽  
Long Term Effects ◽  
Successional Stage ◽  
Protection Measures ◽  
Sand Extraction

Abstract. Sea-level rise demands for protection measures of endangered coastlines crucial for the local population. At the island of Sylt in the SE North Sea, shoreline erosion is compensated by replenishment with sand dredged from an offshore excavation site. We studied the long-term effects of sand extraction on bathymetry, geomorphology, habitats, and benthic fauna. Hydroacoustic surveys revealed that changes of bathymetry and habitat characteristics caused by sand extraction can be still detected after > 35 years while the investigation of grab samples revealed persistent changes in sediment composition and benthic faunal composition. The comparison of recently dredged areas ( 10 years ago) and undisturbed sites exposed significant differences in the number of individuals and species of macrozoobenthic organisms as well as in the mud content, indicating a persistent successional stage of the communities in the dredged areas. The slow backfill of the dredging pits results from low ambient sediment availability and relatively calm hydrodynamic conditions, despite high wave energy during storms. Based on current sedimentation rates, we conclude that a complete backfill of the deep excavation sites and re-establishment of the benthic communities is likely to take centuries in this area. Since re-establishment of the benthic communities depends on previous re-establishment of habitat characteristics, habitat mapping with remote sensing techniques is suggested as a cost-effective means to monitor the state of regeneration.

Estimating Annual Average Daily Bicyclists

2013 ◽  
Vol 2339 (1) ◽  
pp. 90-97 ◽  
Author(s):  
Krista Nordback ◽  
Wesley E. Marshall ◽  
Bruce N. Janson ◽  
Elizabeth Stolz
Keyword(s):  
Cost Effective ◽  
The United States ◽  
Effective Length ◽  
Reliable Estimate ◽  
Annual Average ◽  
Estimation Errors ◽  
Program Cost ◽  
Transportation Funding ◽  
Bicycle Infrastructure ◽  
Safety Studies

Cities around the United States are investing in bicycle infrastructure, and to secure additional transportation funding, cities are reporting bicycle use and safety improvements. Data on bicyclist traffic volume is necessary for performing safety studies and reporting facility use. Meeting the need for data, available manual bicycle counting programs count cyclists for a few hours per year at designated locations. A key issue in the design of counting programs is determining the timing and frequency of counts needed to obtain a reliable estimate of annual average daily bicyclists (AADB). In particular, in which days of the week, hours of the day, and months of the year should counts be collected? And, most important to program cost, how many hours should be counted? This study used continuous bicycle counts from Boulder, Colorado, to estimate AADB and analyze the estimation errors that would be expected from various bicycle-counting scenarios. AADB average estimation errors were found to range from 15% with 4 weeks of continuous count data to 54% when only 1 h of data was collected per year. The study found that the most cost-effective length for short-term bicycle counts is one full week when automated counting devices specifically calibrated for bicycle counting are used. Seasons with higher bicycle volumes have less variation in bicycle counts and thus more accurate estimates.

scholarly journals Investigating the Performance of Enhanced Permeable Groins in Series

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3531
Author(s):  
Manoochehr Shokrian Hajibehzad ◽  
Mahmood Shafai Bejestan ◽  
Vito Ferro
Keyword(s):  
Cost Effective ◽  
Effective Length ◽  
Scour Depth ◽  
Design Guideline ◽  
Scour Holes ◽  
Cost Effective Technique ◽  
In Series ◽  
Proper Design ◽  
Meander Bends ◽  
Deposition Height

The enhanced permeable groin is a novel eco-friendly and cost-effective technique for bank protection and restoration of meander bends. The behavior of bed deformations due to the distance between the structures has to be studied to design enhanced permeable groins in series properly. In this study, scour morphologies around enhanced permeable groins in series, characterized by four different distances and located in a 180° mild flume bend, for clear water conditions were investigated. The analysis indicated that scour geometrical patterns such as the maximum scour depth nearby the structures and the maximum deposition height between them are strongly affected by the distance between the groins. The results revealed that the maximum scour depth around the structures increases with the distance between structures, the scour holes develop towards the outer bank and create a series of pools that can lead to the bank collapse. All experiments, carried out with different structure distances, demonstrated that the location of thalweg effectively shifted towards the middle of the channel and near the inner bank for high and low particle Froude numbers, respectively. As a general result, a distance between enhanced permeable groins equal to four times the effective length of the structure is recommended for a 180° mild flume bend for the investigated particle Froude numbers. Finally, a general design guideline is presented to a proper design of enhanced permeable groins in series.

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