Research Of Calculation Method For Final Soft Clay Port Ground Settlement By Preloading Method

In the areas whose foundation are soft clay, settlement control is one of the keys to guarantee the construction and operation of terminal security. The foundation that has been treated by preloading method processed the foundation bearing capacity, smaller settlement, low cost, and thus are widely used in the soft clay foundation reinforcement works. And the most important question about soft soil foundation processing is how to control the soft soil sedimentation and sedimentation rate. Because of the regional differences of soft-soil, the lack of empirical material, and some other factors, theoretical aspects of research fall behind practice a lot, many solving and forecasting methods’result is not accurate and can not satisfy the need of project.Base on soft foundation treatment project of Yingkou port of Yingkou in Liaoning province, the Calculation Method for Final Soft Clay Port Ground Settlement by Preloading Method is researched and analyzed.1. Test areas are divided into 6 test cell, and each one is tested with different construction parameters according to the monitoring datum to gain the multiple field test and monitored settlement datum. After collating and analysis and finishing the monitoring data, the results show that soft-soil settlement is affected by loading method, filling height and length of drainage plate.2. In order to Eliminate the influence from "abnormal" factors to the monitoring data, wavelet theory is used to disposal the soft soil consolidation settlement value. But the value of settlement is too large for the wavelet theory, so that the concept of differential settlement has been offered in this paper. Three new wavelets including db8 function of Daubechies wavelets, coif4 function of Coiflets wavelets, bior3.7 function of ReverseBior wavelets are used to disposal the soft soil consolidation settlement value respectively, to find out the influence from different wavelet functions and the best wavelet function and decomposition level.3. The settlement value is transformed into differential settlement value on the basis of formula transform which offered possibility to apply the wavelet theory into traditional hyperbola and exponential curve method. Based on the raw and wavelet denoised data, the foundation settlement has been forecasted by hyperbola and exponential curve method and contrasted. We can find out that the precision of hyperbola and exponential curve method is improved by wavelet denoising obviously, and the applicability of the two methods also has been investigated. According to the calculation of hyperbolic method, exponential curve method and stratified summation method, we can get the experience coefficient value range of this place.4. This paper use finite element software ABAQUS, extended linear Drucker-Prager model is introduced to establish three kinds of calculation model with vertical seepage and smear effect considered. The results of this calculation model and measured data are analyzed and compared in the paper to research the correctness and influence of smear effect and vertical seepage of this calculation model.5. According to the forecasting results by hyperbolic method, exponential curve method and stratified summation method, the consolidations degree of 6 experimental area have been calculated, which is used to find out the best the construction parameters of preloading.This paper provide a reference for foundation treatment design and construction in the similar site.