Abstract:Since 1980s, due to loose structures, low degree of consolidation, and over exploitation of groundwater, land subsidence in the northwestern plain of Shandong province has been developing continuiously. The area with the fastest annual settlement rate is located in Guangrao county in the south of Dongying, Boxing county in the south of Binzhou and Muping district in the east of Liaocheng. Ground subsidence funnel in Dezhou is connected with the surrounding Cangzhou and Hengshui settlement areas, and becomes the most typical land subsidence development area in the northwestern plain of Shandong. Among them, the accumulated settlement of the National Cotton Factory monitoring point in Dezhou city has exceeded 1400mm from 1991 to 2017. In this paper, the construction process and monitoring method of the layering marks in Dezhou has been briefly introduced. By using leveling and layering marks monitoring data comprehensively, research on the characteristics of layered settlement has been carried out. It is identified that the ground subsidence rates in the depth of 0~60m, 60~300m, 300~500m and 500m due to compression deformation are 1.67mm/a, 20mm/a, 18.33mm/a and 8.00mm/a respectively. Main factors which caused land subsidence have been analyzed briefly, and suggestions have been put forward for the monitoring of land subsidence in the urban area of Dezhou city.
