## 1 Introduction  
Ensuring that buildings in earthquake areas have good seismic performance has become one of the key tasks for building designers. Currently, the commonly used technical methods include seismic isolation strategy [1; 2; 3], energy dissipation and vibration reduction passive control strategy [4; 5; 6], semi-active control strategy [7], and active control strategy [8]. In comparison with seismic isolation strategy, the passive energy dissipation control strategy possesses the characteristics of having less impact on the construction process and construction time. Moreover, the related energy dissipation devices can be installed after the completion of the main structure. Meanwhile, in contrast to the other two kinds of control strategies, the passive control strategy has the following characteristics: it does not need external energy; relevant technical means are simple and reliable; the subsequent maintenance is extremely simple; and the overall cost is extremely low. In the passive control strategy, in comparison with metal dampers [9] and friction dampers [10; 11], viscous dampers are favored by engineers due to their lack of stiffness and strong energy dissipation capabilities. However, when the structure's deformation is extremely small, or the damper's linking component deformation is extremely large, the damper's deformation will become very small, which cannot efficiently reduce the structure's seismic response [12; 13; 14]. Therefore, it is essential to put forward a damper which not only has a large displacement amplification capability but also has a low stiffness requirement for the brace. The intermediate column damper [15; 16] takes the upper and lower intermediate columns as connecting components for dampers and then installs them within the span of the beam. Therefore, its impact on building functionality is minimal. [PERSON] et al. [17; 18] studied the impact of the position of the column on the damper's displacement and the structure's vibration response as per vibration table experiments. The experimental results were as follows: when the damper system lies at the mid of the beam span, the damping ratio will be the highest, and the structure's inter-story deformation will be the smallest. Other related researchers studied the optimal installation position of dampers in structures. For instance, [PERSON] [19; 20] adopted the artificial bee colony algorithm; [PERSON] [21] applied response surface methodology, and [PERSON] et al. [22; 23; 24] employed the genetic algorithm to seek the dampers' optimal installation location. However, in contrast to the amplification device, the improvement effect on those dampers' displacement produced by the above-mentioned optimization method is poor. Therefore, it is essential to improve the traditional intermediate column damping system to enhance its displacement amplification effect. In order to enhance the damper's displacement, scholars put forward a variety of devices. [PERSON] et al. [25; 26; 27] utilized the slant support level damping system to control the structure's dynamic response and developed a structural optimization design program to realize the structural response close to the optimal control theory. Numerical simulation showed that the seismic response of structures that are equipped with lever damping systems was significantly improved. [PERSON] [28] proposed a symmetrical lever amplification-style oil damper and tested the vibration-reduction effect of the amplification-style oil damper through finite element simulation. [PERSON] et al. [29; 30] designed a lever amplification-style viscous damping wall and conducted a vibration table experiment on a steel frame installed with enlarged viscous damping walls. The results indicated that this amplification device could significantly improve the seismic safety of the structure. Meanwhile, [PERSON] [31] proposed a kind of joint damper with an amplification effect and studied the performance of this enlarged soft steel joint damper through numerical simulation.