Developments of Seismic Design Code for High Pressure Gas Facilities in Japan

Author(s):  
Heki Shibata ◽  
Kohei Suzuki ◽  
Masatoshi Ikeda

The Seismic Design Code for High Pressure Gas Facilities was established in advance of other industrial fields in 1982. Only exception was that for nuclear power plants. In 1995, Hyogoken Nanbu earthquake brought approximately 6,000 deaths and more than 100,000 M$ loss or property in Kobe area, Japan. This unexpected serious event enforced us that industrial facilities should pay to special considerations of their damages including ground failure due to the liquefaction. Their strong ground motions brought serious damages to urban structures in the area. Thus, the Seismic Design Code of the High Pressure Gas Facilities were improved to include 2 step design assessments, that is, Level 1 earthquake (operating basisearthquake, the probable strong earthquake in the service life of the facilities), and Level 2 earthquake (safety shutdownearthquake, the possible strongest earthquake with extremely low probability of occurrence). For Level 2 earthquake, the ground failure by possible liquefaction shall be taken into account. In regard to Level 1 earthquake, the system must be remained safety without critical damage after the earthquake, in addition to no leakage of “gas”. In regard to Level 2 earthquake, the required seismic performance is that peventing systems must be remained without gas leakage, and stable. It means a certain non-elastic deformation without gas leakage may be allowed. The High Pressure Gas Safety Institute of Japan has set up the Seismic Safety Promotion Committee to modify their code in advance of other industries, and continue to investigate more reasonable seismic design practice for more than 5 years. Andthe final version of the guideline has been established for the design practices both in Level 1 and Level 2 earthquakes. This paper explains the activities of the committee, their new design concepts and scope of applications.

2004 ◽  
Vol 126 (1) ◽  
pp. 2-8 ◽  
Author(s):  
Heki Shibata ◽  
Kohei Suzuki ◽  
Masatoshi Ikeda

The Seismic Design Code for High Pressure Gas Facilities was established in 1982 in advance of those in other industrial fields, the only exception being that for nuclear power plants. In 1995, Hyogoken Nanbu earthquake caused approximately 6000 deaths and more than $1 billion (US) loss of property in the Kobe area, Japan. This unexpected disaster underlined the idea that industrial facilities should pay special consideration to damages including ground failure due to the liquefaction. Strong ground motions caused serious damage to urban structures in the area. Thus, the Seismic Design Code of the High Pressure Gas Facilities were improved to include two-step design assessments, that is, for Level 1 earthquakes (operating basis earthquake: a probable strong earthquake during the service life of the facilities), and Level 2 earthquakes (safety shutdown earthquake: a possible strongest earthquake with extremely low probability of occurrence). For Level 2 earthquakes, ground failure by possible liquefaction will be taken into account. For a Level 1 earthquake, the required seismic performance is that the system must remain safe without critical damage after the earthquake, including no gas leakage. For a Level 2 earthquake, the required seismic performance is that the system must remain safe without gas leakage. This means a certain non-elastic deformation without gas leakage may be allowed. The High Pressure Gas Safety Institute of Japan set up the Seismic Safety Promotion Committee to modify their code, in advance of other industries, and has continued to investigate more effective seismic design practices for more than 5 years. The final version of the guidelines has established design practices for the both Level 1 and Level 2 earthquakes. In this paper, the activities of the committee, their new design concepts and scope of applications are explained.


Author(s):  
Y. Namita ◽  
K. Suzuki ◽  
H. Abe ◽  
I. Ichihashi ◽  
M. Shiratori ◽  
...  

In FY 2000, a 3-year testing program of eroded piping was initiated with the following objectives: 1) to ascertain the seismic safety margins for eroded piping designed under the current seismic design code, 2) to clarify the elasto-plastic response and ultimate strength of eroded nuclear piping. A series of tests on eroded piping components and eroded piping systems was planned. In this paper, the results of those tests are presented and analyzed, focusing on the influence of the form and the number of thinned-wall portions on the fatigue life of the piping.


Author(s):  
Y. Namita ◽  
K. Suzuki ◽  
H. Abe ◽  
I. Ichihashi ◽  
M. Shiratori ◽  
...  

In 2000FY, a 3 year program of eroded piping tests was initiated with the following objectives: 1) to ascertain the seismic safety margins for eroded piping designed under the current seismic design code, 2) to clarify the elasto-plastic response and ultimate strength of eroded nuclear piping. It was intended to carry out a series of tests on eroded piping components and eroded piping systems. This paper is a report on the program of eroded piping tests.


2004 ◽  
Vol 126 (1) ◽  
pp. 9-17 ◽  
Author(s):  
Makoto Inaba ◽  
Masatoshi Ikeda ◽  
Nobuyuki Shimizu

After the Great Hyogoken-nanbu Earthquake (1995), the Seismic Design Code for High-Pressure Gas Facilities of Japan was amended. This amended code requires two-step seismic assessments, that is, the evaluation of the Level 1 Required Seismic Performance for Level 1 earthquakes and that of the Level 2 Required Seismic Performance for Level 2 earthquakes. Seismic design of piping systems is newly included within the scope of the code. For Level 2 earthquakes, possible ground displacement due to liquefaction is taken into account. The evaluation method of the Level 1 Required Seismic Performance is specified in the amended code and that of the Level 2 Required Seismic Performance is proposed in the guideline. The evaluation of the former is based on elastic design and that of the latter on elastoplastic design. The propriety of the design criteria of piping systems with respect to ground displacement was confirmed by large deformation tests. In this paper, seismic design criteria of piping systems in the amended code and the evaluation method of the Level 2 Required Seismic Performance proposed in the guideline are introduced, and the results of the large deformation tests are reported.


Author(s):  
Masami Oshima ◽  
Takashi Kase

After Hyogo South Area earthquake, a new seismic design method considering non-elastic deformation behavior is established against Level 2 earthquake (Safety Shutdown Earthquake) in the Seismic Design Code of High-pressure Gas Facilities in Japan. In this paper, this method is applied for an evaluation of existing structures supporting loading-arms in LNG Receiving Terminal. A procedure of pre-earthquake seismic upgrading and modification of the structures that are supported by platforms and supporting loading-arms is introduced. In this evaluation, the seismic loads taking into account of interaction among platforms, structures, and loading-arms are analyzed as total systems. And yield strength design method is applied. Then for the seismic design of loading-arms, floor response spectrums on the installation level are presented. After upgrading the platforms in this case, seismic evaluation of loading-arms based on this study will be performed. So the effect of changing its stiffness is studied. Also to evaluate the dynamic loads subjected to the loading-arms, they are compared with seismic loads that are derived from modified static coefficient method of the seismic design code. Thus with studies of vibration characteristics as total systems, it is possible to make effective and economical countermeasures for pre-earthquake seismic upgrading and modification of the structures and loading-arms.


Author(s):  
Y. Namita ◽  
K. Suzuki ◽  
H. Abe ◽  
I. Ichihashi ◽  
M. Shiratori ◽  
...  

In 2000FY, a 3 year program of eroded piping tests was initiated with the following objectives: 1) to ascertain the seismic safety margins for eroded piping designed under the current seismic design code, 2) to clarify the elasto-plastic response and ultimate strength of eroded nuclear piping. It was intended to carry out a series of tests on eroded piping components and eroded piping systems. This paper is a report on the program of eroded piping tests.


Author(s):  
Makoto Inaba ◽  
Masatoshi Ikeda ◽  
Nobuyuki Shimizu ◽  
Tetsuya Watanabe

After the Great Hyogoken-nanbu Earthquake, “Seismic Design Code for High Pressure Gas Facilities of Japan” was amended. This amended code requires two step seismic assessments, that is, evaluation of Level 1 Required Seismic Performance for Level 1 Earthquake and that of Level 2 Required Seismic Performance for Level 2 Earthquake. Seismic design of piping systems is newly involved in the scope of the code. For Level 2 Earthquake, possible ground displacement due to liquefaction is taken into account. When ground displacement occurs, foundations of structures settle, laterally move or incline as a conseqence, and a piping system supported by independent foundation structures suffers from relative displacements between supporting points, which may exceed several tens of centimeters. The evaluation method of Level 1 Required Seismic Performance is specified in the amended code and that of Level 2 Required Seismic Performance is proposed in the guideline. The former evaluation is based on elastic design and the latter on elasto-plastic design. The propriety of design criteria of piping systems against ground displacement was confirmed by large deformation tests. This paper introduces seismic design criteria of piping systems in the amended code and the evaluation method of Level 2 Required Seismic Performance proposed in the guideline, and also reports the results on the large deformation tests.


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