Comprehensive Research Of Soft Soil Foundation Treatment In NanSha

As the national economic development area, the most important problem need to solve is how to treat with the profound silt and soft clay layers in Nansha area, when we construct building, city road, freeway, underground fourth line.Based on a lot of test data and project examples, the mechanics and engineering characteristic of Nansha soft clay, how to choose the best treatment scheme, the design and calculation of consolidation degree, the estimation and calculation of settlement have been analyzed and debated in this article.The mechanics and engineering characteristic of Nansha soft clay have been summarized though a lot of static explore test, vane cut test and soil test. With the test data of several engineering, correlations between each physics mechanics index with the statistical charts have been analyzed and discussed.Fuzzy mathematics and AHP theories have been introduced, which research non-quantitative analysis theories.Using the Fuzzy mathematics and AHP theories,the tree of affect factor by AHP has been found, the choose of comment subjection degree has been analyzed,the Multi-level Analysis Syn-thetic Fuzzy Evaluation Model has been built.Applying the Expert Consult Method deal with the factors, which have the big influence to the soft ground treatment project, such as the engineering geology (include soft soil thickness, soft soil kinds, etc), the table of factor power has been set up. Through the calculation of three big area soft ground in the Panyu university city of Guangzhou, Nansha economic development area and Zhuhai Power Station, express that this model can provide the reasonable decision for the big area soft ground project.Based on the Terzaghi consolidation theory, The calculating formula of degreed of consolidation of saturation soft clay has been deduced and discussed detailedly when the mode of preloading is instantaneous or classification. A series of calculating theories formula are given with different conditions, such as radial and vertical drainage, total consolidation degree.A few factors that affect the degreed of consolidation of sand well have been discussed. With the soft foundation treatment example of big area in Nansha, the calculation of the total settlement of ground, design calculation of the plastics drains, and average calculation of the degree of consolidation have been analyzed and discussed detailedly.With the monitor data of example, a lot of curve diagrams have been drawn and analyzed of the settlement of shallow layers, deep layers, layered, and the hole water pressure, underground water level. With the monitor data of example, the index curve model and the hyperbola curve model have been applied to estimate the total settlement and last settlement. The two models have their applicability and limit. It has been proved that the index curve model is more accurate than the hyperbola curve model in the aspects of predicting the total settlement and curve match.The modified index curve model has been carried up when the settlement curve present" the step form" with classification preloading. With an example, it proves that making use of the modified model can simulate the step of the settlement curve, reflect time and processes of preloading, just to say it is good with" the step form" as well as the true settlement curve. The effect of instantaneous settlement has been taken into account. The modified model is a good model to estimate to the ground settlement. This model can solve the problem when other models are useless for estimation the settlement of classification preloading.Several conclusion have been gained based on the local test, theory calculation and project application, which were use for the project, especially were use for reference and have extend value in Nansha soil foundation treatment.