PVCO Pipeline Performance Under Large Ground Deformation

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Brad P. Wham ◽  
Christina Argyrou ◽  
Thomas D. O'Rourke ◽  
Harry E. Stewart ◽  
Timothy K. Bond

Technological advances have improved pipeline capacity to accommodate large ground deformation associated with earthquakes, floods, landslides, tunneling, deep excavations, mining, and subsidence. The fabrication of polyvinyl chloride (PVC) piping, for example, can be modified by expanding PVC pipe stock to approximately twice its original diameter, thus causing PVC molecular chains to realign in the circumferential direction. This process yields biaxially oriented polyvinyl chloride (PVCO) pipe with increased circumferential strength, reduced pipe wall thickness, and enhanced cross-sectional flexibility. This paper reports on experiments performed at the Cornell University Large-Scale Lifelines Testing Facility characterizing PVCO pipeline performance in response to large ground deformation. The evaluation was performed on 150-mm (6-in.)-diameter PVCO pipelines with bell-and-spigot joints. The testing procedure included determination of fundamental PVCO material properties, axial joint tension and compression tests, four-point bending tests, and a full-scale fault rupture simulation. The test results show that the performance of segmental PVCO pipelines under large ground deformation is strongly influenced by the axial pullout and compressive load capacity of the joints, as well as their ability to accommodate deflection and joint rotation. The PVCO pipeline performance is quantified in terms of its capacity to accommodate horizontal ground strain, and compared with a statistical characterization of lateral ground strains caused by soil liquefaction during the Canterbury earthquake sequence in New Zealand.

Author(s):  
Brad P. Wham ◽  
Christina Argyrou ◽  
Thomas D. O’Rourke ◽  
Harry E. Stewart ◽  
Timothy K. Bond

Technological advances have improved pipeline capacity to accommodate large ground deformation associated with earthquakes, floods, landslides, tunneling, deep excavations, mining, and subsidence. The fabrication of polyvinyl chloride (PVC) piping, for example, can be modified by expanding PVC pipe stock to approximately twice its original diameter, thus causing PVC molecular chains to realign in the circumferential direction. This process yields biaxially oriented polyvinyl chloride (PVCO) pipe with increased circumferential strength, reduced pipe wall thickness, and enhanced cross-sectional flexibility. This paper reports on experiments performed at the Cornell University Large-Scale Lifelines Testing Facility characterizing PVCO pipeline performance in response to large ground deformation. The evaluation was performed on 150-mm (6-in.)-diameter PVCO pipelines with bell-and-spigot joints. The testing procedure included determination of fundamental PVCO material properties, axial joint tension and compression tests, four-point bending tests, and a full-scale fault rupture simulation. The test results show the performance of segmental PVCO pipelines under large ground deformation is strongly influenced by the axial pullout and compressive load capacity of the joints, as well as their ability to accommodate deflection and joint rotation. The PVCO pipeline performance is quantified in terms of its capacity to accommodate horizontal ground strain, and compared with a statistical characterization of lateral ground strains caused by soil liquefaction during the Canterbury earthquake sequence in New Zealand.


Author(s):  
Rolando Orense ◽  
Suguru Yamada ◽  
Masahide Otsubo

A devastating earthquake hit the Tohoku and Kanto regions of Japan on 11 March 2011, causing extensive damage to life and property as a result of a large-scale tsunami and damage to nuclear power plants. Although located about 400 km away from the epicentre, many residential and commercial buildings and lifeline facilities in Tokyo Bay area suffered extensive damage due to soil liquefaction and associated ground deformation. This paper discusses the results of the damage investigation conducted in the area after the earthquake, with emphasis on liquefaction-induced damage to buildings, roads, lifelines and other infrastructure. In addition, the performance of ground improved by various remediation techniques is discussed. Finally, lessons learned from the event are summarised.


1994 ◽  
Vol 116 (3) ◽  
pp. 154-162 ◽  
Author(s):  
T. M. Hsu

A small-scale, compressive-load test program was conducted at Chevron to determine the strength of tubular members with 1 to 3 holes. The parameters evaluated include the hole size, hole shape, hole location, and number of holes. Results from these tests provide a basis for platform ultimate strength calculations that are needed in making decisions on platform repairs. More than 50 specimens were tested in air under displacment control. Test specimen lengths were limited by the test apparatus to 45 in. (1,143 mm). Tubulars used in the test had an outside diameter of 3.5 in. (89 mm), which gave member slenderness ratios of about 40. The tests were needed because of the lack of relevant compression tests on members with holes. Based on test results, there appears to be a limiting value of hole size below which the compression-load capacity of the member is practically not affected by the existence of the hole. For example, a hole that is 10 percent of the member diameter does not significantly reduce member strength. This means remedial treatment is not necessary for many small holes, when ultimate strength is the controlling consideration. Nonlinear finite element shell analyses using both ADINA and FACTS computer programs and a simplified analysis using DENTA-II PC program were performed and results compared with data. We found that nonlinear finite element programs provide good predictions of capacities of members with holes, and that a simplified DENTA-II program provides adequate and efficient predictions.


2016 ◽  
Vol 23 (5) ◽  
pp. 511-522
Author(s):  
Weifeng Zhao ◽  
Jing Zhou ◽  
Zhilin Long

AbstractThin-walled steel tube/bamboo-plywood composite hollow columns (SBCCs) have excellent physical and mechanical properties. The simple cross section of this composite makes it simple to process and suitable for industrial production. In this paper, axial and eccentric compression tests were conducted on 21 specimens to study the failure characteristics and maximum bearing capacity of this composite. The test results showed that compressive failure in an SBCC is primarily characterized by damage from glue failure at the matrix interface at the end of the column, internal damage of the bamboo-plywood material, damage from glue failure on the tension side in the middle of the column, and buckling damage to the plywood material on the compressive side. The overall adhesive strength between the matrixes primarily determined the failure mode. The maximum bearing capacity of the SBCC generally increased with the net cross-sectional area of the bamboo and decreased with the slenderness ratio and eccentricity. The hollow ratio reduced the slenderness ratio of the test specimens with the same net cross-sectional area of the bamboo and increased the critical compressive load, which significantly improved the compressive load capacity, as was reflected in the slenderness ratio. Finally, a model was formulated based on a non-linear regression analysis of the experimental data. The model was used to determine the allowable compressive capacity of an SBCC to provide guidance for engineering applications.


2016 ◽  
Vol 53 (11) ◽  
pp. 1794-1806 ◽  
Author(s):  
Brad P. Wham ◽  
Christina Argyrou ◽  
Thomas D. O’Rourke

This paper focuses on the effect of tunneling-induced ground deformation on the response of jointed cast iron and ductile iron pipelines that (i) cross the settlement profile perpendicular to the tunnel centerline and (ii) connect through 90° tees with a pipeline parallel to the tunnel centerline. The modeling involves two-dimensional finite element analyses that account for coupled forces both parallel and perpendicular to the pipeline, and incorporates the results of large-scale laboratory tests to characterize the joints. Pipeline response is quantified with respect to joint rotation and pullout at various leakage levels as well as the allowable tensile strain. The paper describes soil displacements induced by a 6.1 m (20 ft.) diameter tunnel in clay and sand. Joint rotations and maximum tensile strains for pipelines in sand exceed those in clay by up to three for the same geometric conditions. Cast iron pipelines crossing the tunnel centerline are most vulnerable to leakage from joint rotation; ductile iron pipelines have sufficient capacity against joint leakage in all cases studied. Cast iron pipelines that connect with 90° tees are highly vulnerable to leakage from pullout due to lateral soil movement. Guidance is provided for risk assessment, design, and utility operations.


Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 2393-PUB
Author(s):  
KENICHIRO TAKAHASHI ◽  
MINORI SHINODA ◽  
RIKA SAKAMOTO ◽  
JUN SUZUKI ◽  
TADASHI YAMAKAWA ◽  
...  

2020 ◽  
Vol 11 (SPL1) ◽  
pp. 847-851
Author(s):  
Nithyanandham Masilamani ◽  
Dhanraj Ganapathy

Middle East Respiratory Syndrome (MERS) induced by new ß coronavirus MERS-(CoV) had first been described in Saudi Arabia in September 2012. MERS-CoV communication inside the population is often identified with clustered households and cramped communal spaces. The purpose of the study is to assess the knowledge and awareness of MERS-CoV among dental students in India. This was a questionnaire-based cross-sectional survey of 100 dental college students in Chennai. The self-designed questionnaires contained ten questions focused on the knowledge and awareness of MERS-CoV amongst dental college students. Questionnaires were circulated through an online website survey planet. After the responses were received from 100 participants, data were collected and analyzed, .87% are aware of MERS-CoV through media 13% from professional channels. 84%are aware of the clinical manifestation of MERS-CoV. 81%Are aware of the mode of transmission of MERS-CoV. 76%are aware of the preventive measures against MERS -CoV.68%. Are aware of the incubation period of MERS-CoV. 74%aware of PCR as a diagnostic test for MERS-CoV. This study concluded that dental students had strong awareness and knowledge of MERS. Also, there are a few differences in information and behaviours that require change. Large-scale health educational programs on MERS also should be facilitated by professional organizations to expand their reach and to strengthen knowledge to have a positive impact on their behaviour.


2019 ◽  
Author(s):  
David Zendle

A variety of practices have recently emerged which are related to both video games and gambling. Most prominent of these are loot boxes. However, a broad range of other activities have recently emerged which are also related to both gambling and video games: esports betting, real-money video gaming, token wagering, social casino play, and watching videos of both loot box opening and gambling on game streaming services like Twitch.Whilst a nascent body of research has established the robust existence of a relationship between loot box spending and both problem gambling and disordered gaming, little research exists which examines whether similar links may exist for the diverse practices outlined above. Furthermore, no research has thus far attempted to estimate the prevalence of these activities.A large-scale survey of a representative sample of UK adults (n=1081) was therefore conducted in order to investigate these issues. Engagement in all measured forms of gambling-like video game practices were significantly associated with both problem gambling and disordered gaming. An aggregate measure of engagement was associated with both these outcomes to a clinically significant degree (r=0.23 and r=0.43). Engagement in gambling-like video game practices appeared widespread, with a 95% confidence interval estimating that 16.3% – 20.9% of the population engaged in these activities at least once in the last year. Engagement in these practices was highly inter-correlated: Individuals who engaged in one practice were likely to engage in several more.Overall, these results suggest that the potential effects of the blurring of lines between video games and gambling should not primarily be understood to be due to the presence of loot boxes in video games. They suggest the existence of a convergent ecosystem of gambling-like video game practices, whose causal relationships with problem gambling and disordered gaming are currently unclear but must urgently be investigated.


2020 ◽  
Vol 47 (3) ◽  
pp. 547-560 ◽  
Author(s):  
Darush Yazdanfar ◽  
Peter Öhman

PurposeThe purpose of this study is to empirically investigate determinants of financial distress among small and medium-sized enterprises (SMEs) during the global financial crisis and post-crisis periods.Design/methodology/approachSeveral statistical methods, including multiple binary logistic regression, were used to analyse a longitudinal cross-sectional panel data set of 3,865 Swedish SMEs operating in five industries over the 2008–2015 period.FindingsThe results suggest that financial distress is influenced by macroeconomic conditions (i.e. the global financial crisis) and, in particular, by various firm-specific characteristics (i.e. performance, financial leverage and financial distress in previous year). However, firm size and industry affiliation have no significant relationship with financial distress.Research limitationsDue to data availability, this study is limited to a sample of Swedish SMEs in five industries covering eight years. Further research could examine the generalizability of these findings by investigating other firms operating in other industries and other countries.Originality/valueThis study is the first to examine determinants of financial distress among SMEs operating in Sweden using data from a large-scale longitudinal cross-sectional database.


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