## 1 Introduction  
Continuous tracks have lower drive autonomy (e.g., steerability and manoeuverability) than wheels; however, they provide a large ground contact area, which reduces the ground contact pressure and increases traction. Therefore, continuous tracks are preferred for heavy vehicles that move on unpaved terrains (i.e., off-road) [1, 2]. On-road vehicles utilize the entire engine thrust as their traction, but the traction of an off-road tracked vehicle is limited by the soil shearing [3]. During operation, the engine thrust is transmitted to the ground through the continuous track, resulting in a shear displacement and associated shear force at the soil-track interface. In the field of terramechanics, they are called the slip displacement and soil thrust, respectively. In most cases, the soil thrust is very small compared to the engine thrust; thus, the soil thrust determines the traction of an off-road tracked vehicle [1, 3, 4]. The shear force of the soil increases as the shear displacement increases until the soil fails. Therefore, a large slip displacement (i.e., a large shear displacement) is required to develop a large soil thrust (i.e., a large shear force). However, the slip displacement prevents the rotation of the continuous track from being converted into the movement of the vehicle; hence, a large slip displacement reduces the driving efficiency. In other words, to improve the tractive performance of an off-road tracked vehicle, sufficient soil thrust must be developed to drive the vehicle with minimum slip displacement. Continuous tracks are usually equipped with grousers to increase traction [1]. Grousers are protruding pads attached to the outer surface of continuous tracks, which increases the soil thrust by generating additional shear force on the side of the track [1,3,4]. As shown in Figure 1, in a continuous track with a grouser, the soil thrusts are developed at the bottom and sides of the soil-track interface (hereafter referred to as bottom thrust and side thrust, respectively). Based on the assumption that a continuous shear failure plane exists along the soil-track interface, the total soil thrust in a continuous track was calculated by differentiating the shear stress developed at the soil-track interface with respect to the area on the bottom (=_vcl_) and the side (=_2 lh_) [1, 2, 3, 4]. Over the last decade, however, several researchers [5, 6, 7, 8, 9, 10] have conducted model track tests, revealing that the soil beneath the continuous track is divided into separate sections. While shearing, rectangular soil blocks are formed between adjacent grousers; each soil block is sheared independently. That is, the shear failure plane at the soil-track interface is not continuous, but segmented. The magnitude of slip displacement and soil thrust experienced by each soil block varies with location. As shown in Figure 2, the soil block located at the front, according to the direction the vehicle moves, experiences little slip displacement (the state where soil shearing is not advanced); hence, the soil thrust is small. The shearing at the soil-track interface increases toward the rear end, resulting in a large slip displacement. Therefore, to obtain the total soil thrust of a continuous track accurately, the soil thrusts of varying magnitudes developed in each soil block must be calculated and added separately. However, the existing method for evaluating the total soil thrust of a continuous track [1, 2, 3, 4] does not consider the independent behaviors of the soil blocks. This results in overestimating the soil thrust, because it calculates the total soil thrust based on the rear end track where the largest slip displacement and soil thrust are likely to occur. To address this, as a continuation of the abovementioned studies [5, 6, 7, 8, 9, 10], we explored a new total soil thrust assessment method for a continuous track considering the independent shearing of soil blocks at the soil-track interface.