【Accident Case】--Illegal earthwork operations

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This post was last edited by yinkuilin6868 on 2015-11-19 at 15:33. Groundwork construction is a common type of activity in enterprises’ safety production processes, and it is quite widespread. In practice, safety accidents often occur due to factors such as inadequate identification of hazards like underground optical cables and hazardous pipelines, illegal operations by construction workers, and poor safety oversight resulting from unclear ownership of the land and discrepancies in the assignment of construction projects. The “7.28” underground pipeline explosion accident in Nanjing, Jiangsu Province is a typical example. As the company undertakes more new projects, renovations, and expansions, resulting in an increase in construction activities, safety risks also rise; therefore, high attention must be paid to the safety management of such construction work. Accident case: The “7.28” underground pipeline explosion accident in Nanjing, Jiangsu Province. Overview of the accident: At around 10:11 on July 28, 2010, while carrying out land leveling and demolition work at the former site of Nanjing Plastic Factory No. 4, located at No. 15, Wanshou Village, Maigaoqiao Sub-district, Qixia District, Nanjing City, Jiangsu Province, Yangzhou Hongyun Construction Support Engineering Co., Ltd.’s excavator punctured an underground propylene pipeline; the leakage of propylene led to an explosion when it came into contact with an open flame. As of July 31, the accident has resulted in 13 deaths and 120 people hospitalized (14 of them with serious injuries). The accident also caused glass in the homes of over 3,000 residents as well as in some shops within a radius of nearly 2 square kilometers to break to varying degrees; the exterior facades of buildings were damaged, and a few steel-frame structures collapsed. Cause analysis (1) Immediate cause: The individual demolition crew unauthorizedly organized the excavation of underground pipelines and gave reckless instructions on site, resulting in the puncturing of the underground propylene pipes. This led to a massive leakage of liquid propylene, and the propylene gas quickly mixed with air to form an explosive mixture that ignited upon contact with an open flame, causing an explosion. (II) Indirect causes: First, the demolition work was carried out in violation of regulations. Second, Plant 4 for plastics failed to stop the reckless excavation work carried out above the propylene pipelines within its premises, despite the fact that the ownership of the land had not changed. Third, when Nanjing Jinling Plastics and Chemicals Co., Ltd. discovered that mechanical construction work was taking place within the premises of Plastic Plant No. 4, which could pose a threat to the safety of the underground propylene pipelines owned by the company, it failed to take effective action to stop such work. It was also unable to accurately identify the location and route of those underground propylene pipelines, thus failing to prevent the accident from occurring. Nature of the accident: This was a serious production safety incident resulting from the illegal carrying out of building demolition work, inadequate safety management and supervision. The demolition contractor, driven by self-interest, altered the scope of its demolition activities without authorization, violated regulations prohibiting underground excavation, and carried out reckless digging during periods when work was suspended. As a result, the pipes used for the normal transport of propylene in chemical production were damaged, leading to a large-scale leak of propylene that caught fire upon contact with open flames. The first lesson is to strictly adhere to the principle of \"local management,\" strengthen the oversight of contractors, enhance training prior to entry into the facility, and reinforce safety supervision during operations, in order to prevent any illegal or irregular practices. Second, strictly implement the work permit management system, strengthen risk analysis and identification prior to operations, and take effective measures to ensure that operational risks are under control. Third, further develop maps showing the distribution and routes of underground pipelines, optical fibers, and cables within the plant area as well as across plant boundaries, improve the basic data archives, and establish reliable protection measures to ensure safety. Fourth, further sort out the situations where construction projects do not match the ownership of the land plots, communicate promptly with relevant external parties, and develop targeted control measures to ensure proper supervision of construction safety. **In response to these requirements, the Office of the State Council Safety Committee issued the \"Notice on the ‘7.28’ Underground Propylene Pipeline Explosion Incident in Nanjing, Jiangsu Province\" on July 31, 2010 (Safety Committee Office [2010] No. 16), setting out various management requirements; excerpts from these requirements are as follows: (1) Strengthen the safety management of ground excavation work in urban areas. With the acceleration of urbanization, ground excavation work in cities and towns has increased significantly. Local authorities should, in light of the fact that urban ground excavation work involves many different departments and entities, further clarify the safety management responsibilities of these departments and entities involved in such work, and ensure that safety supervision duties as well as responsibilities for safe production are fulfilled. Before organizing the construction of a project, the construction project management unit should carefully review relevant documents to fully understand the distribution and layout of underground pipelines in the areas involved in the project, and establish reliable protection measures. For any construction project involving underground pipelines, before work begins, the project management unit must convene the pipeline owners, as well as the parties responsible for construction and on-site safety management, to hold a coordination meeting on safe construction, thereby establishing clear requirements regarding the division of responsibilities for ensuring safe operations. Construction units must carry out their work in strict accordance with safety requirements for construction, and ground excavation is strictly prohibited when the conditions are unknown. The pipeline owner must provide on-site instructions regarding the underground pipelines and place clear markings; if necessary, assign a dedicated person to supervise the work site. Planning and construction departments should establish and improve archives related to urban underground pipeline networks. When planning cities, greater attention should be paid to protecting existing underground pipelines and avoiding conflicts with them, in order to ensure the safety of underground chemical pipelines. (II) Effectively strengthen the safety production of chemical pipelines. Pipeline owners must conduct regular inspections of oil and gas pipelines, strengthen daily patrols of these pipelines, and address any potential hazards promptly to ensure the safe operation of the oil and gas pipelines and their associated facilities. Relevant enterprises must immediately conduct a thorough inspection of all chemical pipelines, improve the labeling and warning signs on these pipelines, and maintain proper documentation. They need to assign clear responsibility for management, carry out regular inspections of the chemical pipelines, and address any issues or potential hazards that are identified promptly. Issues that require **coordinated resolution should be reported to the local authorities promptly**. Safety committees at all local levels should designate the department responsible for overseeing the safety of chemical pipelines within their jurisdictions, and carry out thorough inspections immediately to gain an understanding of the situation regarding these pipelines, including those that pass through public areas as well as those buried underground in such areas. In particular, it is necessary to find out everything related to the underground chemical pipelines in the jurisdiction, and to keep records of this information. Urge the relevant enterprises to further fulfill their responsibilities for safe production and to take effective measures to strengthen management. To address the common issues of illegal structures encroaching on underground chemical pipelines and insufficient safety distances, systematic rectification efforts must be carried out to completely eliminate potential hazards and ensure the safe operation of these pipelines.