## 2 Literature Review
### Risks Associated with Pile Installation  
Several studies examined the risks of pile installation, using different methods in different countries to identify risks. [PERSON] et al. [6] reported the following factors affecting construction risks: history, experience, management stability, team size, resource availability, time compression, and design complexity. In addition, [PERSON] et al. [7] ranked the most relevant risks in bridge construction as financial, external, design, management, construction, contractual, and health and safety risks. In terms of pile construction management, [PERSON] et al. [5] examined and identified the most relevant risks in the construction of a continuous flight auger pile in Egypt using a statistical analysis. They ranked the main risk factors as follows: design, economic, construction, management, owner, political, and subcontractor risks. Based on the forecast of the continuous flight auger pile developed by [PERSON] et al. [8] in Egypt, they used affinity diagramning to recognize cost risks. The total direct cost of the rig, primary loader, pump, mixer, pan, and mini-loader was 59% of the total cost of the pile. At the same time, the site overhead, including supervision, technical staff, and miscellaneous costs, comprised around 35% of the total cost of the pile. Additionally, central office overhead represented around 6% of the total construction cost of the pile [8]. As part of their study, [PERSON] et al. [9] ranked the equipment that influenced the cost as follows: rig, loader, pump, mixer/pan, and mini-loader. [PERSON] et al. [9] studied the risk management of bored piles constructed on sand in Angola. The method used in this study was based on the events' likelihood and economic consequences of specific events. They revealed that the use of a construction method that leads to an unacceptable cost requires applying a risk management policy to provide margin earnings [10]. In Sri Lanka, a case study conducted by [PERSON] et al. [10] utilized a cost-forecasting analysis of the factors affecting a bored pile, including the pile size, drilling time, the depth of the pile, the concrete pouring time, rock socketing, and the type of machine used. [PERSON] and [PERSON] [11] developed a simulation method to determine the production process and cost of constructing a bored pile in the United States of America (USA). The time and cost risk factors predicted by the study's model were the soil type, pile length, pouring method, and auger length. According to two studies by [PERSON] [12] and [PERSON] and [PERSON] [13], the main issues with pile building were undetected subsurface impediments, a lack of contractor experience, and poor site planning. In addition, [PERSON] and [PERSON] [14] developed an artificial neural network (ANN) model to examine several factors that influenced the cost and time of constructing piles utilized for bridge highways. In the KSA, [PERSON] and [PERSON] [15] used an ANN model to evaluate the time and cost risks associated with bored piles. Several studies focused on the impact of noise pollution caused by the installation of piles in coastal environments. The environmental dangers of installing offshore pile foundations were thoroughly reviewed by [PERSON] [16], who focused on the underwater emission of noise. The growing usage of offshore wind energy and the utilization of substantial foundation piles to support wind turbines were explored by [PERSON] [16]. IThe installation of piles creates underwater noise pollution which, the author emphasized, can harm marine life. Hydraulic impact hammers deliver brief pulses to drive the piles into the seabed during impact piling and are the leading cause of the noise. Vibratory machines, which make less noise but still require attention, are also employed for installing piles [16]. The research conducted by [PERSON] et al. [17] aimed to explore and provide practical solutions for reducing pile-driving noise, which is a significant cause of anthropogenic noise in the maritime environment.