Bhaktapur city, one of the historical cities of Nepal, is among the old settlements within Kathmandu Valley that were frequently devastated during major earthquakes. Historical evidence clearly states the high seismic vulnerability of Bhaktapur. So, this study characterizes the free field of the Bhaktapur district in terms of periods. For this, the horizontal to vertical (H/V) technique was used to determine the predominant period of the study area, measuring microtremor data at 200 m × 200 m spacing in the core city area, whereas 400 m × 400 m spacing of measurement was done at the outskirts of the city with rare settlement. The spatial distribution map of the predominant period is prepared with the period obtained from 609 measuring points. The map shows that the predominant period ranges from 0.1 to 4 s and then categorized into four different zones—A (0.10–0.6 s), B (0.6–1.0 s), C (1.0–1.7 s), and D (1.7–4.0 s). The central parts of the study areas are spotted with longer periods (1.7–4.0 s), where the density of the dweller is high. The structural period of 28 reinforced concrete buildings was also determined to understand the level of danger of the buildings due to soil-structure resonance. The predominant period of the buildings ranges from 0.12 to 0.42 s. The possibility of soil structure resonance condition is higher for six buildings, medium for two buildings, and low for the rest of the buildings. The results can be applied to urban planning, seismic hazard mitigation, conservation, and restoration of heritage monuments.

巴克塔普尔市是尼泊尔历史名城之一，是加德满都谷地内的古老定居点之一，经常在大地震中遭到破坏。历史证据清楚地表明巴克塔普尔的地震脆弱性很高。因此，本研究从周期角度描述了巴克塔普尔地区的自由场特征。为此，采用水平垂直（H/V）技术确定研究区的主导周期，在核心城区以200 m×200 m间距测量微震数据，而在核心城区以400 m×400 m测量间距测量微震数据。是在城市郊区完成的，很少有定居点。利用609个测点获得的周期绘制了主导周期的空间分布图。地图显示主要周期范围为 0.1 至 4 秒，然后分为四个不同区域：A（0.10-0.6 秒）、B（0.6-1.0 秒）、C（1.0-1.7 秒）和 D（1.7-1.7 秒）。 4.0 秒）。研究区域的中心部分的周期较长（1.7-4.0 秒），居民密度较高。还确定了28座钢筋混凝土建筑物的结构周期，以了解建筑物因土壤-结构共振而产生的危险程度。建筑物的主周期范围为 0.12 至 0.42 秒。 6栋建筑出现土结构共振条件的可能性较高，2栋建筑中等，其余建筑较低。研究结果可应用于城市规划、减轻地震灾害、保护和修复遗产古迹。