Force Characteristics Of Vertical Maritime Solidified Anchor In Cohesive Beds During Pullout

The performance of anchoring equipment is one of very important issues concerned in coastal and ocean engineering.The stability of offshore floating structures(offshore oil drilling platforms,floating production storage and unloading devices,marine aquaculture cages and underwater suspension tunnels,etc.)and offshore structures(offshore wind farms,etc.)is directly related to the ability to resist wind and waves.Therefore,The choice of anchor with superior performances is of great significance for improving the stability and the ability of marine and coastal structures in order to resist winds and waves.This paper introduces a new kind of anchor which is a vertical maritime solidified anchor patented by our research group.Its structure and working mechanism are presented,which are completely different from those of modern anchors.The pullout resistance and the deformation of the beds surface during pullout are preliminarily proved.It is found that after the installation of vertical maritime solidified anchor,the secondary solidified body,which tightly combines the anchor body with the surrounding beds,significantly increases the shear area of the anchor body,and improves the shear strength of the soil around the anchor body,thus greatly increasing its anchor efficiency.When the anchor is pullout in cohesive bed,the deformation of the bed surface is huge,which makes the failure mode of the bottom bed different from other vertical anchors.According to the theory of optimum selection of solidified agent composition,this paper quantitatively studies the solidified agent,and then obtains the optimum proportion of each component of solidified agent.The optimized solidified agent for vertical maritime solidified anchor has the effect of cementing the anchor body and the bottom bed.The solidified agent has good cementing performance.The cementing product has a strong cementing effect on the soil particles,and the pore filling of the solidified soil body is also closer.This paper compares the pullout force and the failure characteristics of the beds of the anchor with and without solidified agent through the half anchor experiment,accurately depicts the trajectory of the sediment around the anchor during the anchor pullout,and further analyses the stress situation and the change form of the bottom bed at each stage of pullout process of the vertical maritime solidified anchor.In this paper,12 groups of vertical pull-out tests are carried out using four different anchor models.Through the analysis of the experimental results,it is concluded that the anchor structure should have multiple nozzles and the diameter of the nozzle is larger,and the injection speed of the solidified agent should be slower in the installation process.Based on the stress analysis of the pullout process of the vertical maritime solidified anchor,the force balance equation between the resistance and the maximum pullout force of the vertical pullout of the vertical maritime solidified anchor is constructed.Then the experimental data are analyzed by multiple regression,and the formula for calculating the maximum vertical pullout force of the vertical maritime solidified anchor in the cohesive bed is obtained.The formula has good accuracy.