The Assessment of Pipeline Integrity in Geohazard Areas Using ILI Data

2013 ◽  
Author(s):  
Andy Young ◽  
Aaron Lockey
Keyword(s):  
Load Transfer ◽  
Force Component ◽  
Mapping Data ◽  
Transition Zones ◽  
Future Performance ◽  
Analysis Process ◽  
Axial Forces ◽  
Mapping Techniques ◽  
Key Aspects ◽  
Soil Pipe

In-line inspection by inertial mapping techniques is an essential tool for pipeline operators in areas susceptible to geohazards. The detection of previously unknown movements can provide early warning of the presence of a hazard. Positional change and the nature of the loading process can be monitored using the results of multiple inspections over time. Structural modelling is required to fully evaluate the integrity of the pipeline and whether a failure condition is being approached. Finite element techniques can be used, including the effects of soil-pipe interaction, axial forces and operational loads. This enables the prediction of future performance, based on trends from multiple inspections, so that mitigation or intervention methods are efficiently designed and scheduled. This paper considers some key aspects of the analysis process. The use of ILI mapping data to detect small movements below the tool measurement tolerance is examined. The importance of structural analysis is demonstrated by consideration of the axial force component. The inherent variability of the soil surrounding the pipe and its influence on the load transfer effects is illustrated, together with the issues of significant interaction within the transition zones of landslides or faults.

Responses of single piles to tunneling-induced soil movements in sandy ground

2007 ◽  
Vol 44 (10) ◽  
pp. 1224-1241 ◽  
Author(s):  
Kuo-Hui Chiang ◽  
Chung-Jung Lee
Keyword(s):  
Load Transfer ◽  
Bending Moment ◽  
Test Results ◽  
Axial Forces ◽  
Depth Ratio ◽  
Sandy Ground ◽  
Single Piles ◽  
Pile Settlement ◽  
Ground Loss ◽  
Soil Movements

The responses of single piles under various working loads to nearby tunneling were investigated using centrifuge model tests. First, the tunneling-induced soil movements and the tunnel stability in saturated sandy ground were examined. Two instrumented piles with penetration depths of 27 m were located either side of, and at various distances from, tunnels embedded at depths with various cover-to-diameter ratios, and used to measure the bending moments and axial forces at various depths for various ground loss ratios during tunneling simulations. The test results show that in the case of shallow tunneling near a long pile the unit skin frictions on the pile from the tunnel axis to an elevation of 1.5 tunnel diameters above the tunnel axis rapidly decrease with increases in the ground loss ratio. A significant degradation of the end bearing capacity results in a large settlement of the pile if the pile tip is near the tunnel. The depth ratio was found to be a significant influence on the bending moment profiles along the piles, but both the depth ratio and the working loads on the pile head determine the axial load profile and the pile settlement. A mechanism for pile load transfer during new tunneling is proposed to enable construction engineers to prevent structure failure in piles and excessive pile settlement.

scholarly journals Likelihood-based Fits of Folding Transitions (LiFFT) for Biomolecule Mapping Data

2018 ◽  
Author(s):  
Rhiju Das
Keyword(s):  
Small Molecules ◽  
Biological Function ◽  
Visual Assessment ◽  
Supplementary Information ◽  
Chemical Mapping ◽  
Mapping Data ◽  
Modeling Uncertainties ◽  
Multi Wavelength ◽  
Mapping Techniques ◽  
Matlab Package

AbstractSummaryBiomolecules shift their structures as a function of temperature and concentrations of protons, ions, small molecules, proteins, and nucleic acids. These transitions impact or underlie biological function and are being monitored at increasingly high throughput. For example, folding transitions for large collections of RNAs can now be monitored at single residue resolution by chemical mapping techniques. LIkelihood-based Fits of Folding Transitions (LIFFT) quantifies these data through well-defined thermodynamic models. LIFFT implements a Bayesian framework that takes into account data at all measured residues and enables visual assessment of modeling uncertainties that can be overlooked in least-squares fits. The framework is appropriate for multimodal techniques ranging from chemical mapping including multi-wavelength spectroscopy.AvailabilityFreely available MATLAB package at https://ribokit.stanford.edu/LIFFT/[email protected] informationSupplementary data are available at Bioinformatics online.

scholarly journals Rotor Localization and Phase Mapping of Cardiac Excitation Waves Using Deep Neural Networks

2021 ◽  
Vol 12 ◽  
Author(s):  
Jan Lebert ◽  
Namita Ravi ◽  
Flavio H. Fenton ◽  
Jan Christoph
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Optical Mapping ◽  
Simulated Data ◽  
Mapping Data ◽  
Phase Singularities ◽  
Rotor Core ◽  
Phase Mapping ◽  
Spatio Temporal ◽  
Mapping Techniques

The analysis of electrical impulse phenomena in cardiac muscle tissue is important for the diagnosis of heart rhythm disorders and other cardiac pathophysiology. Cardiac mapping techniques acquire local temporal measurements and combine them to visualize the spread of electrophysiological wave phenomena across the heart surface. However, low spatial resolution, sparse measurement locations, noise and other artifacts make it challenging to accurately visualize spatio-temporal activity. For instance, electro-anatomical catheter mapping is severely limited by the sparsity of the measurements, and optical mapping is prone to noise and motion artifacts. In the past, several approaches have been proposed to create more reliable maps from noisy or sparse mapping data. Here, we demonstrate that deep learning can be used to compute phase maps and detect phase singularities in optical mapping videos of ventricular fibrillation, as well as in very noisy, low-resolution and extremely sparse simulated data of reentrant wave chaos mimicking catheter mapping data. The self-supervised deep learning approach is fundamentally different from classical phase mapping techniques. Rather than encoding a phase signal from time-series data, a deep neural network instead learns to directly associate phase maps and the positions of phase singularities with short spatio-temporal sequences of electrical data. We tested several neural network architectures, based on a convolutional neural network (CNN) with an encoding and decoding structure, to predict phase maps or rotor core positions either directly or indirectly via the prediction of phase maps and a subsequent classical calculation of phase singularities. Predictions can be performed across different data, with models being trained on one species and then successfully applied to another, or being trained solely on simulated data and then applied to experimental data. Neural networks provide a promising alternative to conventional phase mapping and rotor core localization methods. Future uses may include the analysis of optical mapping studies in basic cardiovascular research, as well as the mapping of atrial fibrillation in the clinical setting.

Conclusions

2017 ◽  
Author(s):  
Andy Lane ◽  
Sue Oreszczyn
Keyword(s):  
Case Studies ◽  
Participatory Research ◽  
Environmental Sustainability ◽  
Research Process ◽  
Mapping Techniques ◽  
Research Praxis ◽  
Key Aspects ◽  
Systemic Practices

This chapter draws the themes of the book together and, in particular, reflects on the use of the mapping techniques used by the various authors in the book in helping the research process. It highlights key aspects and outcomes from the case studies, and considers the lessons that may be learned for researching environmental sustainability. It discusses mapping, environmental sustainability, systemic practices, participatory research, and methods and methodology. It concludes that although mapping or diagramming is a valued and valuable parts of research praxis into environmental sustainability, this is not the only or better way to do research. The authors express hope that the book inspires readers to apply mapping in complex environmental situations.

Guidance for Non-Intrusive Inspection of Pressure Vessels

2010 ◽  
Author(s):  
Carl E. Jaske
Keyword(s):  
Essential Elements ◽  
Pressure Vessels ◽  
Confined Space ◽  
Inspection Planning ◽  
Mechanical Integrity ◽  
Future Performance ◽  
Integrity Management ◽  
Key Aspects ◽  
Periodic Inspections ◽  
Inspection Techniques

Pressure vessels must undergo periodic inspections to help ensure their mechanical integrity and continued safe operation. Such inspections are usually mandated by regulations or prescribed in the integrity management programs of prudent operators. Traditionally, internal visual inspections have been employed. These can be costly because of the need to shut down the vessel, isolate it, prepare it for entry, and follow requirements for confined-space entry. Furthermore, vessel entry may even have an adverse effect on its future performance. For these reasons, it is desirable to utilize non-intrusive inspection methods where a vessel can be non-invasively inspected from its exterior. However, the use of non-intrusive inspections must not compromise safe and reliable vessel operation. Compared with traditional intrusive internal inspection, non-intrusive inspection is relatively new and there are a wide variety of inspection techniques available. Each technique has its strengths and weaknesses, and many engineers are not fully acquainted with the capabilities and limitations of the various non-intrusive inspection techniques. To address this issue, Recommended Practice DNV-RP-G103 on Non-Intrusive Inspection (NII) was developed [1]. This paper reviews the recommended practice and discusses example applications of the recommended practice. The recommended practice provides guidance on the following key aspects of non-intrusive pressure vessel inspection: (1) determining when its use is appropriate, (2) information that is needed for inspection planning, (3) defining requirements for inspection methods, (4) selecting inspection methods based on requirements, (5) evaluating inspection results, and (6) requirements for proper documentation of inspection results. The essential elements of the procedures covered in the recommended practice are performing a mechanical integrity review, deciding if non-intrusive inspection is possible, planning for the inspection, performing the inspection, and evaluating the results of the inspection. Finally, the inspection interval is evaluated.

Moment-less Arches for Reduced Stress State

2021 ◽  
Author(s):  
Wanda Lewis ◽  
Justin Russell ◽  
Thomas Li
Keyword(s):  
Load Transfer ◽  
Solution Process ◽  
Analytical Form ◽  
Load Resistance ◽  
Shape Prediction ◽  
Axial Forces ◽  
Hoover Dam ◽  
Resistance Moment ◽  
Permanent Load ◽  
Arch Forms

This paper presents a study of two-pin arches of constant cross-section that are moment-less under statistically prevalent (permanent) load. The arches are defined by analytical form-finding previously reported in [1]. The work provides guidance regarding the solution process, and expressions for reactions and axial forces. New analytical results include the derivation of the arch length, and a method for finding co-ordinates of individual arch segments in pre-fabricated construction. The accuracy of the shape prediction for inextensible moment-less arches is good, compared to the results from elastic models. Case studies report on medium and large-span arches, with the latter resembling the iconic Hoover Dam arch. Comparative studies of the moment-less and conventional arch forms (mostly of parabolic configuration), are carried out using permanent and variable loads. Additionally, the Hoover Dam arch is analysed for a discrete load transfer from the deck. Circular arches are analysed for the permanent load only, and are shown to be extremely inefficient in load resistance. Moment-less arches are found to provide a minimal stress response to loading and require least amount of material – a feature observed in natural objects. These characteristics are important from a durability perspective – a key concern for our future infrastructure.

Geometrical Non-Linear Analysis of Truss Structures under 3D Seismic Loads

2014 ◽  
Vol 501-504 ◽  
pp. 1587-1591
Author(s):  
Yong Jiang ◽  
Jian Zhu ◽  
Yan Bin Zhang ◽  
Xin Zhang
Keyword(s):  
Seismic Response ◽  
Time History ◽  
Seismic Loading ◽  
Truss Structures ◽  
Space Structures ◽  
3D Seismic ◽  
Element Analysis ◽  
Analysis Process ◽  
Axial Forces ◽  
Real Earthquake

The seismic response of space structures has been widely studied in the past few years. It has been shown that space structures behave well under seismic loading. However there has been little attention given to the effects of geometrical non-linearity on the seismic response. In this paper, a double-layer truss model was created by finite element analysis program-Lusas. The analysis process took into account of geometrical non-linearity and a 3D seismic loading obtained from a real earthquake. Time-history method was used to investigate the axial forces and displacements of critical members of the model during the earthquake. The seismic behavior of the model and the effect of non-linearity were finally discussed for further applications and studies.

SPC: What is It and Why Should You Use It in Your Xray Analytical Laboratory?

1989 ◽  
Vol 33 ◽  
pp. 537-542
Author(s):  
P. B. DeGroot
Keyword(s):  
Quality Control ◽  
Process Improvement ◽  
Fluorescence Analysis ◽  
Statistical Process ◽  
X Ray ◽  
Future Performance ◽  
Analysis Process ◽  
Analysis Laboratory ◽  
Statistical Approaches ◽  
The U.S

AbstractStatistical Process Control (SPC) methods have become extremely popular in quality control and process improvement in the manufacturing environment, first in Japan and more recently in the U.S. They are gradually being introduced into the research and development setting as well, where they offer some advantages over more traditional statistical approaches. The greatest advantage of the SPC approach is that it ensures that the statistical description generated is valid, i.e., that the data on which it is based incorporate only random error. This is verified both initially and on a continuing basis. This means that the results provide valid predictions of future performance, not just a description of an historical set of replicate samples. SPC statistical evaluations of analytical results and instrument performance require only simple calculations and are easily applied in a consistent, valid manner by statistically unsophisticated analysts. Besides the numerical statistical analysis tools, the SPC approach provides other problem-solving techniques for improvement of the entire analysis process. These aspects of the SPC approach will be described and illustrated with examples from our x-ray fluorescence analysis laboratory.

scholarly journals An Analytical Study of Square CFT Columns in Bracing Connection Subjected to Axial Loading

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Jianrong Pan ◽  
Peng Wang ◽  
Yanjun Zheng ◽  
Zhan Wang ◽  
Deming Liu
Keyword(s):  
Axial Load ◽  
Load Transfer ◽  
Numerical Models ◽  
Axial Loading ◽  
Steel Tube ◽  
Gusset Plate ◽  
Composite Action ◽  
Axial Forces ◽  
Cft Column ◽  
Core Concrete

This paper presents the behavior of square concrete-filled tubular (CFT) columns with different penetrating gusset plates under axial load. Load transfer mechanism in the CFT columns including load distribution between gusset plate and core concrete and composite action of the gusset plate and steel tube was investigated. Experimental results showed that the axial load can be transferred from the bottom edge, ribs, and the hole of the gusset plate to core concrete through the bearing mechanism. Adding ribs or a hole on the gusset plate can efficiently facilitate load transmission and improve the composite action. Numerical models were established to determine the distribution of axial forces among members in the square CFT column. Then, revised coefficients of elastic modulus for the square CFT column with the gusset plate were proposed.

Geogrid-Reinforced Pile-Supported Railway Embankments

2005 ◽  
Vol 1936 (1) ◽  
pp. 221-229 ◽  
Author(s):  
Jie Huang ◽  
Jie Han ◽  
James G. Collin
Keyword(s):  
Load Transfer ◽  
Soft Soil ◽  
Three Dimensional ◽  
Field Measurements ◽  
Failure Criteria ◽  
Organic Soils ◽  
Lagrangian Analysis ◽  
Modeling And Analysis ◽  
Axial Forces ◽  
Lateral Displacements

Piles or columns have been used successfully in combination with geosynthetics to support embankments over soft soil. The inclusion of geosynthetic reinforcement over piles enhances load transfer from soil to piles, reduces total and differential settlements, and increases slope stability. It creates a more economical alternative than that without the geosynthetic. An existing geosynthetic-reinforced pile-supported embankment in Berlin was selected for numerical modeling and analysis. This embankment was constructed to support railways over deep deposits of peat and soft organic soils. Precast piles and caps were installed with a load transfer platform formed by three layers of geogrid and granular materials installed between the piles and the embankment fill. Instrumentation was installed to monitor the settlements of the embankment and the strains in the geogrid layers over time. A finite difference method, incorporated in the fast Lagrangian analysis of continua three-dimensional software, was used to model this embankment. In the numerical analysis, piles were modeled with pile elements, and caps were modeled as an elastic material. Geogrid elements built in the software were used to represent the geogrid reinforcement. Embankment fill, soft soil, firm soil, and platform fill material were modeled as linearly elastic perfectly plastic materials with Mohr–Coulomb failure criteria. The embankment was built by a number of lifts to simulate its construction. Numerical results and comparisons with field measurements on the vertical and lateral displacements, the tension along the reinforcement, and the axial forces and moments on piles are presented.

Sign in / Sign up

Export Citation Format

Share Document