Experiment Of The Lateral Bearing Capacity Of Jetting Conductor And Finite Element Analysis Of Soil Strength Reduction

In jetting conductor technology, the damage of water jet to soil results in not onlysinking of the conductor by its own weight, but also weakening the strength of soilaround the conductor; thus the horizontal bearing capacity of the conductor is affected.Until now, there were few reports about the effects of horizontal bearing capacityunder different jetting parameters. Therefore, the problem was studied in this workusing both of the model test and finite element simulation analyses.The main content includes:1. Based on the pile foundation theory, this thesis introduces three classicstheories about calculating the lateral bearing capacity of conductor. On the basis of thejetting theory, the breaking mechanism and influence to the soil are analyzed underwater jeeting.2. The model and equipments, which are needed in the experiment, weredesigned successively. According to the specified test plan,26times effective testswere completed. After organized and analysed all tests information, the curves and theresults, which is needed to analyse, were obtained and are discussed in this paper.3. By comparing the model test results, the relationship between lateral bearingcapacity and hydraulic parameters are discoverd, which include water displacement,nozzle diameter and jet velocity. Besides, some general objective laws are obtained. Inthis paper, some regression equations are given in view of there are quite a number ofdata.4. PLAXIS2D, a professional geotechnical finite element software, is used inthis paper. By gradually reducing the strength parameters of soil, a series of workingstate were found, which are similar to experiment results. According to these states,the reduction factors of soil strength parameters are estimated, and some general lawsbetween reduction factors and hydraulic parameters are summarized. Furthermore,some regression equations are given in view of some set of parameters, which includequite a number of data.Through the study of this paper, some meaningful conclusions are received aboutdeep water jet drilling technology, which can provide assistance for further theoreticalresearch and engineering practice.