## 1 Introduction  
Fault ruptures are caused by sudden movement on a fault, when stress on the edge overcomes the friction, and energy in waves are released and travel through the soil. In recent years, there has been an increasing amount of research on this topic due to several major incidents, such as fault ruptures in Taiwan in 1999, Turkey in 1999, the USA in 2002, Japan in 2004, China in 2008, and in Iran in 1990 [1; 2; 3; 4; 5; 6]. Furthermore, in 2015, an earthquake with a magnitude of 6 occurred in Sabah, Malaysia, which was recorded as the second largest earthquake in the country after the 1991 earthquake in Ranau, which was also in Sabah [7]. A tectonic map of fault activity revealed that Sabah's fault was part of a 200 km-long system of normal faults that crosses the eastern side of the Crocker Range, parallel to Sabah's northwest coastline [8]. Two types of physical models, namely, centrifuge and 1g models, have been used in previous studies on fault ruptures [9; 10]. The centrifuge model has the ability to change the centrifuge's acceleration, \(Ng\), where \(N\) stands for the scaling factor and g stands for the acceleration of gravity. It means that a unit weight of soil in the centrifuge is \(N\) times the unit weight at 1g [11; 12; 13; 14; 15; 16]. It involves changing gravity to simulate a real situation. However, fault simulations with centrifuge tests were mostly used to investigate free fields (fields without any structures) and cohesionless soil [13; 15; 17]. Several studies have examined the relationship between shear zone and damages, and the findings show that soil experiences the highest stress and strain in the shear zone, which causes damages to soil. [PERSON] et al. used the centrifuge model for an experimental investigation to explore the shear zone when faults happen in a free field, and he showed that soil density can have a major influence on ground surface displacements [18]. The 1g model is more preferred to be used for simulating the effect of soil properties on tunnels induced by faults. Firstly, unlike the centrifuge model, which is very sensitive to achieve certain gravity, natural gravity is used in the 1g model. Secondly, the process of increasing the vertical component in the 1g model can be manipulated, and also, more gauges can be installed in the 1g model due to its larger size. Thirdly, the effects of various soil properties can be investigated more accurately as it involves greater mass of soil. Investigation on the effects of soil properties alone shows that deformations of wet and dry soil when a fault happens are different. It was found that wet soil shows a major increase in piston pressure compared to dry soil, illustrating that wet soil increases the soil strength [19]. Soil density is another important aspect of soil failure. The shear zone in low-density soil is typically more complex than in high-density soil, and as the relative density of the ground model becomes more significant, the number of rupture planes decrease because soil strength does not allow more fractures in the soil [9; 11]. Furthermore, soil properties such as cohesion, friction angle, particle size, density, and water contents are very important in any simulation and analysis involving soil [20; 21]. Results from previous studies have shown that changing of soil friction angles and cohesion could affect the bearing capacity of soil [22; 23]. The results from [PERSON] et al. showed that cohesion is very important to be measured in underground structures because cohesion increases with depth and each layer of soil has different cohesion [24]. Furthermore, soil particle size and water content have been claimed to have critical impacts in designing foundations, roads, and other infrastructure [25; 26]. Moreover, normal and reverse faults would also have different impacts on soil deformations. When a normal fault happens, at least one rupture propagation reaches the ground surface and damages building foundations, and there could be more impacts on the soil [10; 27].