Keywords

1 Introduction

One of the main tasks of construction is the rational use of resources. This issue becomes especially important during war or hostilities.

The industrial building suffered threatening destruction as a result of a missile attack on the workshop facilities at the end of 2022. In order to restore the functioning of the workshop, it became necessary to carry out dismantling and restoration works of the load-bearing and enclosing building structures.

The affected site is systematically divided into four work sections, emphasizing areas most impacted by the rocket attack. Following the completion of emergency measures, specialists conduct a comprehensive diagnosis of structures beyond the hazardous zone, providing an approximate assessment of the scope of emergency demolition works.

The consequences of the damage are presented in (Fig. 1). The characteristics of the constructive and object-planning solution of the facility are provided in Table 1.The existing roof of the building is made of ribbed precast concrete slabs measuring 3 × 6 m. On top of the slabs, there is 80 mm insulation, 20 mm cement screed, and four layers of roofing felt on bitumen mastic. The roof slabs are welded to the trusses at three points. The dismantled building is conditionally divided into 6 sections (Fig. 2).

Fig. 1.
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Nature of object destruction.

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Fig. 2.
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The diagram and 3d scheme of the building being restored (divided into sections).

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2 Analysis of Recent Research

In this study, we created methodology for the emergency dismantling of industrial facilities impacted by military activities, a subject that remains largely unexplored within the current corpus of research.

Recent literary sources on the research topic demonstrate a consistent trend towards so-called “green dismantling” and recycling of materials generated as a result of dismantling. For instance, the article [1] describes a methodology for developing a dismantling plan and minimizing CO2 emissions during the dismantling process.Authors in article [2] describe new technologies for dismantling concrete structures that utilize sound-absorbing chemical agents to minimize the environmental and health impacts of dismantling activities. The article outlines the main components of these agents and their influence on the dismantling process, as well as presents an environmental impact assessment system.

Article [3] investigates and explains the dismantling practices in cities in the United States and Germany, while article [4] presents solutions based on completed projects in Ukraine. While article [3] focuses more on economic aspects and typology, article [5] highlights the need for selective dismantling, which involves disassembling buildings into components and materials for further reuse. The dismantling practices issue is also discussed using examples from China, the Czech Republic and other countries [6,7,8]. Another important topic is the technical assessment of residual resources of dismantled buildings [9, 10]. Timely conducted technical assessment can serve as a legal basis for. can identify reserves for their further utilization [9]. Accurate information on the composition (quantity and quality) of materials is necessary for designing the subsequent use of construction materials obtained from building and structure dismantling [10]. In the research conducted [11], quantitative data on the activities of reuse, recycling, and demolition of construction materials have been analyzed.

Table 1. Characteristics of the destroyed object
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To create structures and buildings with high transformability and dismantling potential, more effort needs to be focused on the development of prefabricated elements and building systems to support the potential for transformation during possible dismantling stages [12]. A successful example of addressing waste disposal and overall waste management can be seen in the case of AZS company (Czech Republic) [13]. An attempt to summarize current trends in the field of construction waste recycling is being conducted in the work [14].

Considering demolition as a stage preceding the main construction process, several authors in their works focus on the issues of designing the technology and making key decisions regarding the dismantling and destruction of building elements, with a special emphasis on controllability, safety, and process efficiency.

In the work [15], the corresponding requirements are outlined to ensure the specified conditions when choosing the method of building demolition, many factors to be considered. The article [16] presents the process of mechanical demolition through step-by-step investigation and structural collapse. Initially, the structure is weakened in a cross-section using a cutter, and then it is brought down by applying lateral (horizontal) loading. Demolishing structures in this manner allows for the maximum amount of material to be recycled.

The work [17] introduces a Java application with a Building Information Modelling-based Deconstruction Assessment Score (BIM-DAS) to assess the deconstructability of structures during the design stage. Additionally, careful image pre-processing can remove noise and smooth the original information for later analysis [18,19,20].

Recent studies mainly address standard dismantling and construction waste recycling, overlooking emergency scenarios. This article aims to show how conventional dismantling technologies and digital tools can be adapted for use in sites damaged by the missile strike. The identified research gap in emergency dismantling underlines the importance of exploring advanced technologies for managing industrial crises.

3 Results and Discussion

In the first hours following the occurrence of an emergency situation, ensuring the safety of personnel and the environment becomes the primary concern. To achieve this, the following actions needed to be taken as soon as possible: 1) disconnect all utilities and power systems in the building; 2) extinguish the fire resulting from the explosion of the missile; 3) assess the extent of damage to the building; 4) identify key issues and develop a plan for the dismantling of destroyed and damaged structures; 5) disconnect all utilities and power systems in the building.

Since an emergency situation had arisen, it was necessary to expedite the process of dismantling the affected structures to minimize potential consequences such as environmental pollution and the risk of damaging other buildings and systems on the premises.

The first step was to dismantle the damaged structures and equipment that could potentially pose a danger, such as falling structures or damaged power systems.

Subsequently, the dismantling process was carried out step by step, taking into account the specific characteristics of the building and potential risks.

The building was conventionally divided into 4 general work sections, with the areas most affected by the rocket attack highlighted in purple. The schematics of the most affected site are shown in Fig. 3a, 3b. After completing all the emergency measures, specialists conducted a diagnosis of the structures located outside the hazardous zone of the collapsed emergency structures. After the inspection and examination, an approximate assessment of the scope of emergency works was carried out (Table 2).

At the next stage, it was necessary to remove the already collapsed structures and those that were partially destroyed but still secured and posed a risk of collapse (Fig. 4a, 4b). This was done in order to subsequently install cranes and safely proceed with the demolition of less affected structures.

The next task was to dismantle the remaining structures that were attached to the frame, such as wall panels and beams, which were in a critical condition and at risk of collapse at any time. In general, the dismantling technology for panels at considerable height (7 m and above) is not significantly different from installation, except that it is performed in reverse order and involves the following steps: 1) establishing a safety perimeter around the hazardous zone, with a distance of 7 m from the building; 2) installing a crane and a hydraulic lift; 3) assessing the condition of the panel and identifying its attachment points to the building; 4) rigging the structure to be dismantled, which involves creating openings in the structure or welding lifting lugs to metal parts of the panel, and ensuring proper tensioning of the rigging.

However, in the current conditions, it is not feasible to use this technology because the panels are severely damaged and lack structural rigidity. Even if they could be rigged, when cutting the embedded parts, they may collapse in any direction, posing a risk to construction machinery and workers involved in the dismantling operations. In such cases, it is advisable to use mechanical demolition by excavators. However, even a 30–40-ton excavator with a standard boom would not be able to handle the task, as the upper panels are situated at a significant height (over 17 m), and the excavator would need to be positioned outside the hazardous zone, i.e., at a radius of more than 7 m from the hazardous structures.

Fig. 3.
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a. The 1st section (diagrams of before and after destruction), b. The 3rd section (diagrams of structures structures before and after destruction)

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Fig. 4.
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a. Clearing the site from the demolished structures (photo before), b. Photo of the site after clearing.

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One of the presented solutions is the use of an excavator with an extended boom for demolition works. The diagram for demolition using an excavator with an extended boom is shown below (Fig. 5). The technology for carrying out work during the dismantling of panels using an excavator with a boom extension involves the following steps: 1) recting a stable enclosure around the work area; 2) attaching the boom extension instead of the bucket; 3) driving the excavator into the demolition zone;4) securing the damaged wall panels using the boom extension and using the excavator’s hydraulic system to lower them to ground level; 5) after completing the dismantling, moving to another parking area.

Using another excavator equipped with a hydraulic hammer positioned outside the dangerous zone of panel collapse to further process the panels into a convenient size for loading and transportation.

After the dismantling of the hanging damaged panels, the next step is to gradually dismantle the damaged fencing structures. During the inspection, it was found that the roofing panels have also been damaged and are in a critical condition, making it impossible for workers to be on the roof. Therefore, the standard method of dismantling a part of the roofing panels cannot be used when workers are present on or under the roof covering. To dismantle the structures, high-capacity crawler cranes of 100 and 250 tons with movable hooks were selected and utilized. The main feature of these cranes is that they have two hook suspensions on one hook (Fig. 6), each with its own mechanism (brake, winch, safety device). One hook is used to suspend a work platform with workers, while the other can be used to attach the dismantled panel.

Table 2. Approximate estimate of emergency demolition works
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Fig. 5.
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Photo of the boom extension

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This technology was adopted for the dismantling of the damaged panels at this site. The work execution scheme is shown (Fig. 7).

Fig. 6.
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Winch arrangement diagram.

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Fig. 7.
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Scheme of dismantling the roof panels.

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When we have completed the dismantling of the parts of the building that were in an emergency state, it became possible to move on to the dismantling of the surviving parts of the coating, which are set aside for dismantling. The following work method can partially overcome this problem. The task was to remove the coating/metal sheets in undamaged areas and out of reach of the crane. To solve this task, the following technological scheme was adopted for performing working a specialized cart.

Preparatory work: 1) Inspect the roof, if it is in satisfactory condition and can accommodate workers; 2) Workers climb onto the roof using existing ladders. 3) Secure safety ropes to existing structures and place wooden planks on the roof (Fig. 8a). Workers must be constantly secured with a safety harness attached to the structure or the installed safety rope. 4) Attach specialized safety systems (Fig. 8b) to existing structures.

Fig. 8.
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a. Scheme for installing ladder, b. Schemes of specialized safety systems.

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The principle of the safety system is that it allows free movement for the worker, stretches under normal movement speed, but if the speed exceeds 1 m/s (falling speed), it stops (brakes are activated) and keeps the harness taut. 5) Install guide rails for the workers (Fig. 9a). 6) Position the trolley on the guide rails in the working position (Fig. 9).

Main technological process: 1) Position the carriage above the plate/sheet to be dismantled. 2) Make holes for slinging in the reinforced concrete plate and weld attachment points on the metal sheet. 3) Sling the plate/sheet using the hooks attached to the carriage. 4) Separate the reinforced concrete plate using manual tools (break the joints and trim embedded parts). For metal sheets, detach their embedded parts. 5) Lift the detached sheet 200–300 mm from the roof using the hoists. 6) Transport the detached sheet along the rail tracks using the carriage to the crane work area. 7) Lower the plate/sheet onto the roof and release it from the slings in the crane work area. 8) Remove the plate/sheet using the crane in storage area.

Fig. 9.
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Dismantling scheme of reinforced concrete panels/metal sheets using a specialized carriage.

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4 Conclusions

Summing up the highlights of the project efficiency, with the dismantling of 2470 tons of metal structures, coverings, beams, and crane equipment, along with nearly 650 m3 of prefabricated and monolithic concrete structures, and also replaced nearly 7,800 m2 of damaged covering concrete slabs on metal sheets completed within a four-month period in complex industrial conditions. This underscores the method’s effectiveness and potential for broader application.

The study provides a detailed exploration of the methodologies necessary for addressing the consequences of incidents at industrial complexes, specifically focusing on the dismantling of structures within a facility compromised by a missile strike. By introducing advanced technological strategies, the research significantly reduces the need for manual labor, maximizes the effectiveness of construction machinery, and notably improves on-site safety conditions. These technological advancements are versatile, making them suitable for a wide range of industrial settings, thus underscoring the universal applicability of the proposed solutions. The applicability of these technological schemes extends across diverse industrial environments, highlighting the broad relevance of the study. Future research will aim to develop a systematic framework and typology for the dismantling methods applicable to both industrial and civilian infrastructures, thereby contributing to the standardization and efficiency of dismantling practices globally. Moreover, the integration of digital tools and real-time data analysis is anticipated to further streamline the dismantling process, enabling more precise decision-making and enhancing operational agility in response to unforeseen challenges.