Study On Axial Force And Safety Monitoring Model For Super Sized Deep-water Pile-group Foundation

Deep-water pile-group foundation is applied for great span bridges at large. With upscating of bridge building, pile group foundation is developing for over-length, great diameter and super size. However design experience and theory of the foundation lag behind the engineering practices. So it is attached general importance to its safety. Perfect safety monitoring system is installed to ensure the safety of the foundation and groundsill. Based on the under study National Basic Research Program of China(973 Program)—'Basic Research on the Safety of Major Engineering Project in Hazardous Environments' andJiangsu Provincial Traffic Science Study Program-------'the KeyTechniques Study on Supersized boring pile-group foundation', take the building super size deep-water pile-group foundation of Sutong Bridge as example, Combined with the site safety monitoring, several problems are studied as follows:1. For the gross errors of observed data, the model of gross errors identifying for axial force of piles is founded based on Phase Space Reconstruction and One class Classification of SVM. It is one of the innovation points in this paper.2. For pile-group foundation of tide reaching zone, Tide affects its bear characteristic evidently. The monitoring results must be adjusted according to tidal changes in-order to study the relativity of axial force of piles and load of upside structure. After getting a great deal of observed data of piles axial force and tide, a method of tidal adjustment for variety wire sensors is advised. This is another innovation of this paper.3. Basing on deepgoing analysis of observed axial force value, the bear characteristic and distribute rule of foundation piles is researched during concreting the pier base and cable tower. It is the basis of analysis on pile group effects.4. The final and excellent innovation of this paper is to found the monitoring model of tip axial force of single piles, the plane distribution monitoring model of tip axial force of pile group and the depth distribution monitoring model of axial force of single foundation piles.5. Axial force of foundation piles are predicted according to the monitoring model. The errors between predicted data and simulated data accord with normal distribution. When observed stylebook is greater than 30, lower than 30 and lower than 16, Three-