Design Parameter Analysis And Soil Pressure Research Of Pile-anchor Support System

For the building foundation pit of urban construction projects, its security and stability must be ensured firstly, and it does not have the harmful influence to the environment. However, the economic aspects are also significant. The pile-anchor bracing system is often used in engineering, and the analysis of its design parameters and the earth pressure is still an important topic.Based on the actual pile-anchor bracing excavation, the following research work was carried out by using numerical simulation method:1. Firstly, the equivalent beam method was used to the design of pile-anchor bracing structure. Secondly, the three-dimensional finite element model of the pile-anchor bracing foundation was established. The influences of supporting structure parameters, such as the supporting pile diameter, pre-stress size of the anchor, anchorage body's elastic modulus, on the horizontal displacement and internal force were analyzed. Thirdly, the corner effect was considered, and the optimization analysis of the bracing structure was made. The analysis results show that by adjusting the related design parameters and utilizing of foundation pit corner effect appropriately, it can reduce the usage amount of the materials and make full use of material properties.2. For the pile-anchor bracing system, a typical pile-soil element of the project and its 3-D numerical model was established. The earth pressure and displacement of the pile body was obtained. The influences of the anchor prestress, anchor point position and ground overload on the earth pressure was analyzed. The results show that the three factors have comparatively large effect to the displacement and the earth pressure above the excavated plane, and have little influence on the passive earth pressure. Pile body displacement and the size of earth pressure exists certain corresponding relation.3. The comparison of the two numerical models shows that the modeling methods have their application areas. The methods can obtain the displacement, inner force and earth pressure of the bracing system respectively, so it should be employed neatly.