## 1 Introduction  
With the process of urbanization and the rapid development of social economy and culture, the transportation of large numbers of people has brought great pressure to urban road traffic, and therefore many cities are vigorously developing public transportation. Bus rapid transit (BRT), as a new and efficient public transport mode, has achieved remarkable results in improving urban transport efficiency and relieving traffic pressure due to its capacity, feasibility and cost-effectiveness. As a key component of this development, BRT-related research has basically focused on land development impact [1], greenhouse gas emissions [2], safety concerns [3], life cycle cost assessment [4] and comparison with other public transport alternatives [5]. However, little work has been done to study the mechanical characteristics of BRT roads until recent years. The difficulty lies in the combination of special factors that affect BRT roads that can significantly accelerate the deterioration of BRT pavements. In the current operation situation, ruts, potholes, fatigue cracks and other damage develop in many BRT roads shortly after they are put into service. This phenomenon is even more serious in station areas of BRT systems [6, 7]. Due to the frequent braking and starting of buses, severe rutting can cause early pavement failure. As a result, [PERSON] et al. [8] and [PERSON] et al. [9] suggested using high-modulus asphalt concrete in the asphalt pavement structure to inhibit rutting and fatigue cracking. Such research has great significance for the prevention of BRT asphalt pavement problems. However, in addition to the asphalt material, other factors including axle weight, axle type, running characteristics of BRT vehicles and environmental temperature have a significant impact on the mechanical characteristics of BRT asphalt pavement. Most pavement problems are related to the temperature of the pavement structure and the characteristics of bus loads. Regarding pavement structure temperature, many scholars have conducted meaningful research. [PERSON] et al. (2010), [PERSON] et al. (2011), and [PERSON] et al. (2012) focused on the relationship between asphalt pavement temperature and the urban heat island effect and showed that asphalt pavement was vulnerable to atmospheric temperatures. [PERSON] et al. (2013), [PERSON] et al. (2014), and [PERSON] et al. (2015) researched factors influencing pavement surface temperature, including air temperature, solar radiation, wind speed, and pavement texture. [PERSON] et al. (2016), [PERSON] et al. (2017), [PERSON] et al. (2018, 2019), and [PERSON] et al. (2010) introduced models for predicting asphalt pavement temperature. [PERSON] et al. (2011) and [PERSON] et al. (2012) studied the influence of the temperature field on the stress of asphalt pavement structures. [PERSON] et al. (2013) quantified the thermal behavior of continuously reinforced concrete pavement (CRCP) and the curling deflection of BRT lanes. [PERSON] (2014) measured and analyzed the relationship between the surface temperatures of different pavement types and atmospheric temperature. Another factor that has an important effect on the mechanical properties of BRT asphalt pavement structure is the bus load. Bus loads in urban areas have the characteristics of heavier axle weight, slow speeds, and frequent acceleration and deceleration (2015), which are obviously different from the characteristics of highway vehicle loads (2016; 2017). Meanwhile, due to width limitations of lanes and the size of buses, the load must be concentrated on the wheel path, and this highly channelized load has an adverse effect on BRT pavement structure. Therefore, for the mechanical analysis of BRT asphalt pavement structure, it is necessary to use a traffic load that is more in line with the characteristics of BRT buses. However, research on load characteristics of BRT vehicles is limited. With respect to vehicle loading, [PERSON] et al. (2018) and [PERSON] et al.