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Procedia Engineering 142 ( 2016 ) 161 – 165

Sustainable Development of Civil, Urban and Transportation Engineering Conference Investigation on the Key Response Factors of Action Plan in Underground Pipeline Emergency Scenario

Yeong-Nain Sheena, Her-Yung Wanga, Chun-Hung Chena,*

aDepartment of Civil Engineering, National University of Applied Sciences, Kaohsiung, 8867,

Abstract

Kaohsiung gas explosion caused serious fatalities, making this the largest petrochemical catastrophe in Taiwan’s history. It raises a concern how we can make better /best decision to reduce the fatalities and property loss in such little time. Through the literature, little research has been done in evaluating the decision making. The paper mainly focuses on what are the key response factors in terms of action plan. This paper adopted Delphi method in order to gain the wisdoms of experts so as to formulate the important decision-making factors. Firstly, the Delphi method was conducted to gain consensus of experts out of three categories. Through the back and forth procedure, we modified the factors based on the opinion of experts. Secondly, after confirming the 13 factors, questionnaire issued to the experts to gain their individual’s values. Finally, after analyzing the questionnaire, the result shows that ‘Jet water to disperse the gas’ is the top priority. © 20162016 The The Authors. Authors. Published Published by Elsevierby Elsevier Ltd. LtdThis. is an open access article under the CC BY-NC-ND license (Peerhttp://creativecommons.org/licenses/by-nc-nd/4.0/-review under responsibility of the organizing). committee of CUTE 2016. Peer-review under responsibility of the organizing committee of CUTE 2016 Keywords: Key response factors; Delphi method; underground pipeline incident;

1. Introduction

A series of gas explosions occurred in the southern Taiwanese city of Kaohsiung on 31 July 2014. Fig. 1 shows the location and explosion area where the incident occurred. Prior to the incident happened, a smell of gas and white smoke came out of manholes near Kaisyuan 3rd Road and Ersheng 1st Road in Cianjhen . Residents near by the scene reported the odd smell to Kaohsiung Fire Department at 8:46 p.m. Fire fighters, including those from nearby City, have rushed to the scene [1]. They sprayed water on the roads to lower the gas concentration and also secured the nearby area to prohibit any heat source. In order to find out leak source, Kaohsiung Fire

* Corresponding author. Tel.: +886-7-3814526~5236; fax:+886-7-3961294. E-mail address: [email protected]

1877-7058 © 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the organizing committee of CUTE 2016 doi: 10.1016/j.proeng.2016.02.027 162 Yeong-Nain Sheen et al. / Procedia Engineering 142 ( 2016 ) 161 – 165

Department required Kaohsiung Public Works Bureau to provide pipeline map data. Staff in Environment Protection Agency (EPA) and experts of Southern District Disaster Response Team went to scene sampling at 9:30 p.m. The leak gas was sampled and confirmed Alkenes not until 11:50 p.m. The explosions occurred later at 11:56 p.m. on Yisin Road, Ersheng Road, Sanduo Road and Guanghua Road. The blasts, which were triggered by underground gas leaks, tore trenches through main roads, overturned cars and trucks[2]. Fig. 2 shows the blasts spilt roads in two and overturned vehicles. About 6km of road length were damaged. Images of the scene showed major fires, upturned vehicles, bodies covered in debris [3]. Among the many casualties from the blasts were members of Kaohsiung’s police and fire departments [4]. During the incident, 32 people were killed and 321 others were injured.

Fig. 1. The location and explosion area of the incident Fig. 2. The blasts spilt roads in two and overturned vehicles

. Several points have raised and criticized by the public:

x The pipeline map data was established by Kaohsiung Public Works Bureau failed to provide the exact data. x Three pipeline companies claimed nothing unusual in its pipeline and refused to shut down the pipeline when civilian reported odd smell to 119. x The government was eager to find out the leak source so as to take proper procedure rather than evacuating in the first time.

The question now arises. How can we make better /best decision in such little time to reduce the fatalities and property loss? The purpose of this paper is to explore selecting the response factors in such incident. It is hoped that the findings can contribute to successful rescue and thus reduce casualties.

2. Relevant incidents

Through the literature, there are also several devastating pipeline gas explosion cases [5-7]. On November 19, 1984, in Mexico City, a ruptured LPG pipeline released large amounts of liquefied petroleum gas. The gas continued leaking and formed vapor cloud and eventually caused a powerful explosion. The explosion killed 550 people and injured 221. The 1992 explosion in Guadalajara, Mexico's second largest city, took place on April 22, 1992. Due to the erosion of oil pipeline, large amounts of gasoline vapor spread through sewer system. Over four hours, numerous gasoline explosions occurred in the sewer system and destroyed 8 kilometers of streets in the downtown. A large area gas explosion in metropolitan city was first seen. Officially, 206 people were killed; nearly 500 injured. The Qingdao oil pipeline explosion occurred on 22 November 2013. An oil pipe leaked at 2:40 a.m. The underground Yeong-Nain Sheen et al. / Procedia Engineering 142 ( 2016 ) 161 – 165 163 pipeline ruptured and crude oil leaked onto a street. Before the pipeline was shut down at 3:15 a.m., oil had infiltrated into underground utility pipes. Eventually it caught fire and exploded. The blast killed at least 62 people.

3. Methodology

3.1. Scope of the research

Although the cases of gas explosion are quite a few, the relevant research mainly from prevention perspective to reduce the risk, thus prevent the incident happening again in the future. However, little research has been done from rescue perspective. While taking proper decision making in during-incident phase is also crucial in order to reduce casualties and property loss. The scope of this study focus on what are the key response factors of action plan should be taken into consideration.

3.2. Delphi method

The objective is to develop a technique to obtain the most reliable consensus of experts. Since there are no relevant study has been done before, this research applied Delphi method to gain the key response factors. The main reason is that Delphi method has proven a useful tool in decision making. It originally developed as a systematic, interactive forecasting method which relies on a panel of experts [8,9]. It uses the qualitative research methods to quantify the group consensus. The purpose of the paper is to gain the wisdom of experts to reach consensus. It is a group decision mechanism requiring qualified experts who have deep understanding of the issues [10]. Therefore, one of the most critical requirements is the selection of qualified experts. This paper primarily based guidelines initially developed by Delbecq et al [11]. It is a small group approach. Delbecq et al. suggested the ideal group size is 5-7 individuals. A Delphi study does not depend on many samples to reflect any population. Moreover, it is based on a structured group of individuals are more accurate than those from unstructured groups [12].

3.3. Data collection and analysis method

The Delphi questionnaires will be mainly administered using e-mail and fax. Schmidt et al. [13] outlined the procedure for “ranking-type’’. This will involve three general steps: (1) brainstorming for important factors; (2) narrowing down the original list to the most important ones; and (3) ranking the list of important factors. Questionnaire was adopted a five-point Likert scale. In questionnaire 1 phase, experts were treated as individuals, not panels. The questionnaire is blank so they were free to write down important factors based on their profession in view of “Actio n plan”. Since the experts were anonymous, the experts were encouraged to write down their opinions based on their knowledge and experience. After the first round of expert questionnaires were collected, unlike other questionnaire, the statistics began. After each round, the statistics data of the experts’ group opinions from the previous round would be provided. Thus, experts were encouraged to revise their earlier answers in view of the replies of other members so as to collect the key response factors.

4. Results and discussions

In this case, three relevant categories of experts who have important and valuable knowledge/experience in this field were selected. The selection of qualification showed in Table 1. Through the Delphi method, the gap of the answers would decrease and the solution would focus. Experts rated the most important factors to least from 5 points to 1 point. The higher the score indicate that the experts agree the factor is more important. While the mean scores of factor is less than 3 points, indicating the impact factor is less important. It should be removed. If the coefficient of variation is less than 0.3, indicating that experts have reached a high degree of consensus; coefficient of variation between 0.3 to 0.5, indicating that the results can be acceptable; if the coefficient of variation is greater than 0.5, indicating that the results are inconsistent. The factor needs to be 164 Yeong-Nain Sheen et al. / Procedia Engineering 142 ( 2016 ) 161 – 165

eliminated. After retrieving the first Delphi questionnaire, we removed exact duplicates and unified terminology, and list the relevant factors to consolidate so as to issue questionnaire 2.

Table 1. The selection of qualified experts. Categories Amount Qualifications Academics 5 They are Chemical disaster experts and have served as instructor in fire department. Industrials 5 People serve in chemical industry and work as manager class. Experienced firefighter 5 Firefighter officers have practical experience and had been the commander of pipeline gas leak incident. officers

After that, the questionnaires 2 list all the consolidated factors and send to experts for validation. Through the back and forth process, based on the feedback of experts, we modified and refined the consolidated factors. After revising the returned questionnaire 3, we gained the factors of final version. For instance, Table 2 showed the 13 factors of action plan.

Table 2. Factors of action plan in final version questionnaire 4. Final version Questionnaire 4 Factors of 1. Jet water to disperse the gas. Action Plan 2. Make deployment at an upwind or side wind location. 3. Protect the peripheral equipment at risk such as gas stations. 4. Prevent the gas from flowing into the MRT, underpass and other underground structures. 5. Wear Level-A (high temperature resistant) protective clothing during proposal. 6. Wear fire-protection clothing and shoes including SCBA during proposal. 7. Use the stationary turret and people retreat to locations with safety protection in place. 8. Close the shutoff valve emergently. 9. Stop the leakage at the leakage source. 10. Shut down the oil, gas and electric power supply in accordance with the needs. 11. Contain, divert and rescue the water in use. 12. Use the computer software to estimate the leakage amount and leakage range. 13. Monitor the leakage state of the hazardous environment at fixed points or fixed times.

By consolidating the important factors, we managed to issue questionnaire 4 to collect judgment value of each expert. After receiving questionnaire 4 back from experts, we calculated the values of mean and coefficient of variation. Table 3 presents the values of each response factors.

Table 3. Values of mean and coefficient of variation Phase Factors Mean Coefficien t of Variation Action plan Jet water to disperse the gas 4.87 0.07 Make deployment at an upwind or sidewind location 4.8 0.09 Protect the peripheral equipment at risk such as gas stations 3.33 0.19 Prevent the gas from flowing into the MRT, underpass and other underground structures 3.8 0.18 Wear Level-A (high temperature resistant) protective clothing during proposal 3.33 0.22 Wear fire-protection clothing and shoes including SCBA during proposal 3.6 0.18 Use the stationary turret and people retreat to locations with safety protection in place 3.87 0.19 Yeong-Nain Sheen et al. / Procedia Engineering 142 ( 2016 ) 161 – 165 165

Close the shutoff valve emergently 4.33 0.14 Stop the leakage at the leakage source 4.07 0.11 Shut down the oil, gas and electric power supply in accordance with the needs 3.73 0.16 Contain, divert and rescue the water in use 3.13 0.2 Use the computer software to estimate the leakage amount and leakage range 3.33 0.27 Monitor the leakage state of the hazardous environment at fixed points or fixed times 3.53 0.18

5. Conclusions

In this paper, we applied the Delphi method to conduct the research hoping to find out the primary consideration factors in during-accident phase. Use of the Delphi method for factors building gained 13 factors, These factors should be adopted in decision-making when encounter an underground pipeline gas leak incident. Conclusions derived from the feedback of experts show that: x 13 key response factors, which are selected from experts out of 3 different fields, need to be taken into action when answer to the underground pipeline gas leakage accident. Moreover, it list the score for emergency responder to do decision making. x Among the 13 factors in action plan, “Jet water to disperse the gas” gains the highest consensus of experts. That means it should be done as soon as possible. x While the score of “Make deployment at an upwind or side wind location” is also noticeable. It gains the second highest score among all. Besides, “Close the shutoff valve emergently” is also critical factor to diminish the explosion risk. Not many researches have been done in gas explosion rescue. This research only addresses the action plan stage while there are still many stages need to investigate and clarify in such complicated and time bound rescue environment. It requires further study. Moreover, future work will hopefully broaden the scope and clarify the priorities in every stage of rescue.

References

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