A New Design Method for Piping Components Against Leakage and Damage Subjected to High Level Earthquake Load

2002 ◽  
Author(s):  
Fumio Ando ◽  
Toshiyuki Sawa ◽  
Masatoshi Ikeda
Keyword(s):  
Failure Modes ◽  
Design Method ◽  
Bending Moment ◽  
Practical Method ◽  
Shaking Table ◽  
Inertia Force ◽  
Expansion Joints ◽  
Gas Leakage ◽  
Earthquake Load ◽  
Petroleum Refineries

A design method of piping components for Level 2 earthquake (the possible strongest earthquake with extremely low probability of occurrence) such as bolted flanged joints, expansion joints, and equipment nozzles is described. This design method is provided taking into account their failure modes and degree of safety. The failure modes for each piping component is classified according to the past damage experience due to earthquake, and each criterion is provided against the failure mode. The typical failure modes are gas leakage, fatigue failure, cumulative plastic deformation during and after earthquake for bolted flanged joints, expansion joints and equipment nozzles in piping components, respectively. Specifically, the simplified method of bolted flanged joints is proposed as the convenient design method for chemical plants and petroleum refineries, etc. (here in after calls as plant) The method is derived using gasket factor, gasket dimensions and clamping forces due to bolts for external piping load. This practical method is investigated and verified due to the experimental results on the welding neck type flanges subjected to static bending moment, in which the bolted flanged joints of NPS 4″ and 8″ in size, 3 types of gaskets are used. In addition, the dynamic inertia force effect is also studied by the shaking table tests using cantilever model of bolted flanged joints at fixed side with changing the bolt clamping forces and gasket types.

DESIGN OF BOLTED CONNECTIONS SUBJECT TO TORSION AND SHEAR IN THE ULTIMATE LIMIT STRESS STATE

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Mohamed S. Abu-Yosef ◽  
Ezzeldin Y. Sayed-Ahmed ◽  
Emam A. Soliman
Keyword(s):  
Failure Modes ◽  
Focal Point ◽  
Design Method ◽  
Limit State ◽  
Bending Moment ◽  
Steel Structures ◽  
Ultimate Limit State ◽  
Shear Forces ◽  
Limit States ◽  
Ultimate Limit

Steel connections transferring axial and shear forces in addition to bending moment and/or torsional moment are widely used in steel structures. Thus, design of such eccentric connections has become the focal point of any researches. Nonetheless, behavior of eccentric connections subjected to shear forces and torsion in the ultimate limit state is still ambiguous. Most design codes of practice still conservatively use the common elastic analysis for design of the said connections even in the ultimate limit states. Yet, there are some exceptions such as the design method proposed by CAN/CSA-S16-14 which gives tabulated design aid for the ultimate limit state design of these connections based on an empirical equation that is derived for ¾ inch diameter A325 bearing type bolts and A36 steel plates. It was argued that results can also be used with a margin of error for other grade bolts of different sizes and steel of other grades. As such, in this paper, the performance of bolted connection subject to shear and torsion is experimentally investigated. The behavior, failure modes and factors affecting both are scrutinized. Twelve connections subject to shear and torsion with different bolts configurations and diameters are experimentally tested to failure. The accuracy of the currently available design equations proposed is compared to the outcomes of these tests.

scholarly journals Static and Dynamic Response of Micropiles Used for Reinforcing Slopes

2021 ◽  
Vol 11 (14) ◽  
pp. 6341
Author(s):  
Tong Yang ◽  
Yuming Men ◽  
Cassandra J. Rutherford ◽  
Zhen Zhang
Keyword(s):  
Dynamic Response ◽  
Failure Modes ◽  
Load Transfer ◽  
Progressive Failure ◽  
Earth Pressure ◽  
Bending Moment ◽  
Model Tests ◽  
Shaking Table ◽  
Loading Conditions ◽  
Group Effect

To study the static and dynamic response of micropile-reinforced slopes, static model tests and shaking table tests were performed. The failure modes, the pile-slope interaction, the displacement, and the static/dynamic earth pressure distributions were analyzed based on static and dynamic model tests with a prescribed sliding surface. The test results indicated: (1) The micropile failure mode is mainly bending failure under both loading conditions. As far as the damage to the pile body is concerned, under static loading, the rear row piles showed more damage than the middle row piles followed by the front row piles. Under dynamic loading, the damage of the rear row piles was approximately the same as the middle row piles, which was greater than the front row piles; (2) The earth pressures in front of and behind each row of micropiles and the axial force of the pile body distributed triangularly for both loading conditions, with the bending moment of the pile body distributed in an “S” shape; (3) The landslide thrust experienced by the micropiles has a relatively large group effect. The group effect or shear ratio parameters are recommended for each loading case; (4) The interaction between the micropiles and the soil landslide presents evident progressive failure and load transfer between the rows.

Centrifuge Modeling on Seismic Behavior of Pile in Liquefiable Soil Ground

2013 ◽  
Vol 479-480 ◽  
pp. 1139-1143
Author(s):  
Wen Yi Hung ◽  
Chung Jung Lee ◽  
Wen Ya Chung ◽  
Chen Hui Tsai ◽  
Ting Chen ◽  
...  
Keyword(s):  
Seismic Behavior ◽  
Soil Structure ◽  
Lateral Displacement ◽  
Bending Moment ◽  
Soil Liquefaction ◽  
Centrifuge Modeling ◽  
Shaking Table ◽  
Pile Head ◽  
Liquefiable Soil ◽  
Tip Mass

Dramatic failure of pile foundations caused by the soil liquefaction was founded leading to many studies for investigating the seismic behavior of pile. The failures were often accompanied with settlement, lateral displacement and tilting of superstructures. Therefore soil-structure interaction effects must be properly considered in the pile design. Two tests by using the centrifuge shaking table were conducted at an acceleration field of 80 g to investigate the seismic response of piles attached with different tip mass and embedded in liquefied or non-liquefied deposits during shaking. It was found that the maximum bending moment of pile occurs at the depth of 4 m and 5 m for dry sand and saturated sand models, respectively. The more tip mass leads to the more lateral displacement of pile head and the more residual bending moment.

Submarine Pipeline Installation JIP: Strength and Deformation Capacity of Pipes Passing Over the S-Lay Vessel Stinger

2006 ◽  
Author(s):  
Enrico Torselletti ◽  
Luigino Vitali ◽  
Erik Levold ◽  
Kim J. Mo̸rk
Keyword(s):  
Water Depth ◽  
Failure Modes ◽  
Bending Moment ◽  
External Pressure ◽  
Submarine Pipeline ◽  
Design Guideline ◽  
Moment Capacity ◽  
Sea Bottom ◽  
Major Vessel ◽  
Gas Fields

The development of deep water gas fields using trunklines to carry the gas to the markets is sometime limited by the feasibility/economics of the construction phase. In particular there is a market for using S-lay vessels in water depth larger than 1000m. The S-lay feasibility depends on the applicable tension at the tensioner which is a function of water depth, stinger length and stinger curvature (for given stinger length by its curvature). This means that, without major vessel up-grading and to avoid too long stingers that are prone to damages caused by environmental loads, the application of larger stinger curvatures than presently allowed by current regulations/state of the art is needed. The work presented in this paper is a result of the project “Development of a Design Guideline for Submarine Pipeline Installation” sponsored by STATOIL and HYDRO. The technical activities are performed in co-operation by DNV, STATOIL and SNAMPROGETTI. The scope of the project is to produce a LRFD (Load Resistant Factor Design) design guideline to be used in the definition and application of design criteria for the laying phase e.g. to S and J-lay methods/equipment. The guideline covers D/t from 15 to 45 and applied strains over the overbend in excess of 0.5%. This paper addresses the failure modes relevant for combined high curvatures/strains, axial, external pressure and local forces due to roller over the stinger of an S-lay vessel and to sea bottom contacts, particularly: • Residual pipe ovality after laying, • Maximum strain and bending moment capacity. Analytical equations are proposed in accordance with DNV OS F101 philosophy and design format.

Preliminary Parametric Assessment of a Bolted Endplate Joint under Combined Axial Force and Cyclic Bending Moment

2011 ◽  
Vol 255-260 ◽  
pp. 718-721
Author(s):  
Z.Y. Wang ◽  
Q.Y. Wang
Keyword(s):  
Finite Element Analysis ◽  
Axial Force ◽  
Seismic Design ◽  
Axial Load ◽  
Failure Modes ◽  
Bending Moment ◽  
Element Analysis ◽  
Cyclic Behaviour ◽  
Joint Behaviour ◽  
Steel Joints

Problems regarding the combined axial force and bending moment for the behaviour of semi-rigid steel joints under service loading have been recognized in recent studies. As an extended research on the cyclic behaviour of a bolted endplate joint, this study is performed relating to the contribution of column axial force on the cyclic behaviour of the joint. Using finite element analysis, the deteriorations of the joint performance have been evaluated. The preliminary parametric study of the joint is conducted with the consideration of flexibility of the column flange. The column axial force was observed to significantly influence the joint behaviour when the bending of the column flange dominates the failure modes. The reductions of moment resistance predicted by numerical analysis have been compared with codified suggestions. Comments have been made for further consideration of the influence of column axial load in seismic design of bolted endplate joints.

Research on Friction between Grade Flat Approach Slab and Sliding Material in Jointless Bridges

2019 ◽  
Author(s):  
Yufeng Tang ◽  
Bruno Briseghella ◽  
Junqing Xue ◽  
Peiquan Zhang ◽  
Fuyun Huang ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Life Cycle Cost ◽  
Bending Moment ◽  
Horizontal Displacement ◽  
Element Model ◽  
Expansion Joints ◽  
Approach Slab ◽  
Jointless Bridges ◽  
Friction Function ◽  
The Mathematical Model

<p>The application of jointless bridges has been increasing year by year, because it could reduce the life‐cycle cost and improve the riding comfort. The approach slab in jointless bridges does not only have the function of road transition which is the same as the approach slab in bridges with expansion joints, but also transfer and absorb the deformation produced by the thermal expansion and contraction of the girder. The Grade Flat Approach Slab (GFAS) horizontally placed on the subgrade is one of the most common types of the approach slab in jointless bridges. The material placed between GFAS and subgrade should be able to properly slide to reduce the stress in GFAS. The friction coefficient between GFAS and sliding material is an important parameter affecting the mechanical behavior of GFAS in jointless bridges. In this paper, the tests of GFAS with different sliding materials subjected to horizontal displacement were conducted to obtain the corresponding friction coefficients (from 0.34 to 0.68). The mathematical model of bilinear spring could be adapted to simulate the friction function between GFAS and different sliding materials. One Deck‐Extension Bridge (DEB) that is one type of jointless bridges was chosen as a case study. The finite element model was implemented by using Midas‐Civil software. The influence of GFAS with different sliding materials on the mechanical properties of DEB under temperature variation was investigated. It can be concluded that the influence of the friction coefficient between GFAS and sliding material on the bending moment of DEB should be taken into account.</p>

Seismic Response of Pile Groups Improved with Deep Cement mixing Columns in Liquefiable Sand: Shaking Table Tests

2021 ◽  
Author(s):  
Dingwen Zhang ◽  
Anhui Wang ◽  
Xuanming Ding
Keyword(s):  
Seismic Behavior ◽  
Lateral Displacement ◽  
Bending Moment ◽  
Pile Group ◽  
Shaking Table ◽  
Excess Pore Pressure ◽  
Shaking Table Tests ◽  
Pile Groups ◽  
Acceleration Response ◽  
Table Model

A series of shaking table model tests were performed to examine the effects of deep cement mixing (DCM) columns with different reinforcement depths on the seismic behavior of a pile group in liquefiable sand. Due to the DCM column reinforcement, the fundamental natural frequency of the model ground increases noticeably. The excess pore pressure of soils reduces with the increase of reinforcement depths of the DCM columns. Before liquefaction, the acceleration response of soils in the improved cases is obviously lower than that in the unimproved case, but the acceleration attenuation is greater after liquefaction in the unimproved case. Moreover, the lateral displacement of the superstructure, the settlement of the raft, and the bending moment of the piles in the improved cases are significantly reduced compared to those in the unimproved case, and the reduction ratios rise with the increase of reinforcement depth of the DCM columns. However, reinforcement by the DCM columns may result in the variation of the location of the maximum moment that occurs in the pile.

scholarly journals Tests and Analyses of Slotted-In Steel-Plate Connections in Composite Timber Shear Wall Panels

2017 ◽  
Vol 2017 ◽  
pp. 1-20
Author(s):  
Ulf Arne Girhammar ◽  
Bo Källsner
Keyword(s):  
Bearing Capacity ◽  
Failure Modes ◽  
Design Method ◽  
Shear Walls ◽  
Test Results ◽  
Horizontal Shear ◽  
Load Bearing Capacity ◽  
Wood Panel ◽  
Load Bearing ◽  
Plate Connections

The authors present an experimental and analytical study of slotted-in connections for joining walls in the Masonite flexible building (MFB) system. These connections are used for splicing wall elements and for tying down uplifting forces and resisting horizontal shear forces in stabilizing walls. The connection plates are inserted in a perimeter slot in the PlyBoard™ panel (a composite laminated wood panel) and fixed mechanically with screw fasteners. The load-bearing capacity of the slotted-in connection is determined experimentally and derived analytically for different failure modes. The test results show ductile postpeak load-slip characteristics, indicating that a plastic design method can be applied to calculate the horizontal load-bearing capacity of this type of shear walls.

Multi Mode Vibration Control and Broder Band Motion Control of Three Dimensional Shaking Table

2005 ◽  
Author(s):  
Tsunehiro Wakasugi ◽  
Toru Watanabe ◽  
Kazuto Seto
Keyword(s):  
Vibration Control ◽  
Controller Design ◽  
Design Method ◽  
Three Dimensional ◽  
Design Procedure ◽  
Equation System ◽  
State Equation ◽  
Shaking Table ◽  
Mode Vibration ◽  
And Control

This paper deals with a new system design method for motion and vibration control of a three-dimensional flexible shaking table. An integrated modeling and controller design procedure for flexible shaking table system is presented. An experimental three-dimensional shaking table is built. “Reduced-Order Physical Model” procedure is adopted. A state equation system model is composed and a feedback controller is designed by applying LQI control law to achieve simultaneous motion and vibration control. Adding a feedforward, two-degree-of-freedom control system is designed. Computer simulations and control experiments are carried out and the effectiveness of the presented procedure is investigated. The robustness of the system is also investigated.

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