# Study of Lead Rubber Bearings for Vibration Reduction in High-Tech Factories
## 1 Introduction  
The lead rubber bearing (LRB) has the advantage of increasing a building's natural period, which is away from the seismic period range, to avoid the amplification caused by earthquakes, so it is ideal to reduce seismic loads using LRBs for high-tech factories. However, the LRB may increase environmental vibrations induced by moving vehicles and wind loads, which will damage the high-tech production. In the literature, the issue of LRBs for high-tech factories is rarely studied. However, LRBs have many references in building and bridge research and testing. [PERSON] et al. [1; 2] demonstrated the bridge isolation design process that can be applied to all earthquakes and used the numerical simulation of LRB bridges to obtain the long-term periodic displacement and effective damping, due to LRBs, which can improve the seismic capacity of general bridges. [PERSON] et al. [3] conducted a base isolation test for a building and found that LRBs can effectively reduce the building response. [PERSON] et al. [4] used LRB numerical simulation on eight-layer structures to propose that the structure increases the natural period to avoid the shortest period of earthquake damage. [PERSON] et al. [5] proposed a theory that predicts the dependence of feature intensity and energy time to predict the behavior of LRBs to simplify the analysis. [PERSON] and [PERSON] [6] proposed the necessary conditions for reducing the LRB scaling test and the need to consider the temperature rise of the lead core. [PERSON] et al. [7] made a multi-layer building foundation combined with finite element simulations of LRBs, suggesting that this isolation technology has the ability to survive buildings under strong earthquakes. [PERSON] et al. [8] studied the rational yield ratio of isolation system for buildings, considering the influencesof total heights, yield ratios, and seismically isolated schemes, and the rational range of the yield ratio is recommended to be 2%-3%. In a number of references, correlation studies on the effects of LRB parameters are used to understand the best design parameters. [PERSON] et al. [9] studied the relationship between lateral displacement and vertical stiffness of LRB and found that the vertical stiffness decreases with the increase of lateral displacement. [PERSON] and [PERSON] [10] conducted experiments and numerical simulations to understand the relationship between LRB critical loads and lateral displacements and found that the critical loads decrease with the increase of lateral displacements. [PERSON] and [PERSON] [11] proposed that LRB systems with higher characteristic strength and relatively less isolation periods behave better to reduce structural offset, and LRBs with lower characteristic strength and a high isolation period can control the basic shear, providing a small acceleration and low inertia. Several references investigated the biaxial interactions of LRBs, which is convenient for understanding interaction effects. [PERSON] et al. [12] considered the formula proposed by [PERSON] to simulate the biaxial interaction of LRB. [PERSON] et al. [13] proposed a two-way simulation formula for LRBs and made some experiments to compare the uniaxial and biaxial effects. [PERSON] et al. [14] conducted a biaxial test on LRBs to understand the effect of the torsional coupling effect. It is suggested that the two-axis interaction cannot be ignored. [PERSON] and [PERSON] [15] used the experiment to verify the effectiveness of an isolation system made of polymeric bearings in reducing structural vibrations and demonstrated that the application of this bearing can significantly reduce the lateral acceleration. Although the application of LRBs is quite mature, there is very little or probably no research that focuses on high-tech factories directly. The reason is because the equipment used to produce high-tech productions requires strict micro-vibration standards, but it is unclear whether micro-vibration will increase significantly when LRBs are installed in high-tech factories.