Compared with conventional piles such as the circle pile, the cast-in-place large-diameter pile (PCC pile) has many advantages: the lateral area of PCC pile is larger and the bearing capacity of PCC pile is higher. It is more cost-effective than other piles such as square pile under the same condition. The deformation of the PCC pile is very important for its application. In order to obtain the deformation of the PCC pile, a new type of quasi-distributed optical fiber sensing technology named a fiber Bragg grating (FBG) is used to monitor the deformation of the PCC pile. The PCC model pile is made, the packaging process of the PCC model pile and the layout of fiber sensors are designed, and the strains of the PCC model pile based on FBG sensors are monitored. The strain of the PCC pile is analyzed by the static load test. The results show that FBG technology is successfully applied for monitoring the deformation of the PCC pile, the monitoring data is more useful for the PCC pile. It will provide a reference for the engineering applications.

Saline soil is a special soil that consists of fine particles and has poor engineering properties. It causes salt heaving and is collapsible and corrosive. The treatment of this type of soil for the use as a resource for roadbed fillings has been one of the most important engineering topics in highway construction near coastal areas. This study introduces a new type of aqueous polymer, called ZM, which is used to amend and stabilize saline soil. To test the effects of ZM-solidified saline soil, unconfined compressive strength (UCS) tests were carried out on unmodified and ZM-modified saline soil specimens, respectively. The test results show that the ZM additive significantly improves the UCS. Based on the increase of the ZM admixture, the UCS increases with the curing time. The main increment of the UCS occurs within the first seven days of curing. In addition, the salt content has a great influence on the UCS. With increasing ZM concentration and curing time, the water stability and wetting-drying cycling resistance improve. Based on the X-ray diffraction results, the diffraction peaks of ZM-modified saline soil insignificantly change compared with those of unmodified saline soil. However, the SEM images indicate the formation of membrane structures in ZM-modified saline soil. The modification process produces denser and more stable soil because the reaction products fill voids inside the soil and form a viscous membrane structure on the soil surface.