Taking the YD002 borehole in Tongzhou Bay area of Jiangsu Province as the research object, this paper establishes a DFOS (distributed fiber optic sensing) system of land subsidence to monitor the deformation and subsidence of Quaternary sedimentary layer in this area for a long time. Based on the monitoring data, the current situation and trend of land subsidence in this area are studied and analyzed. The results show that the main deformation source in this area is the compression deformation of the soil layer caused by the vertical water release of the confined aquifer group in the upper part of the main pumping layer. The whole stratum shows a compression trend, and the deformation of each compression layer is closely related to the variation law of groundwater level. Compared with the traditional layer-wise mark, the DFOS technology can more finely measure the vertical compression and rebound deformation of soil layer.

In order to study the anti-disintegration properties of biological glue modified clay, xanthan gum, guar gum, and mixed composite glue of xanthan gum and guar gum mass with ratio of 1:1 were used to improve the clay. Through the anti-disintegration test, the effects of biological glue content, type and compaction degree on the anti-disintegration properties of improved clay were investigated, and the improvement mechanism of biological glue was further analyzed by scanning electron microscopy test. The results show that the biological glue enhances the anti-disintegration property of the sample by enhancing the cohesion between soil particles. The collapse failure process can be divided into the pre-stable collapse stage, stable collapse stage and post-stable collapse stage. With the increase of biological glue content, the disintegration stage of the improved clay is prolonged, the disintegration rate slows down, and the disintegration rate decreases. The disintegration resistance of the modified composite adhesive is stronger than that of single biological adhesive when the content is greater than 1.0%. With the increase of compaction degree, the disintegration resistance of the sample is obviously improved.