西安黄土土性相关距离的统计分布特性研究

土性指标概率模型参数的确定是进行岩土工程可靠度分析和设计的基础。为了更好地推行岩土工程可靠度设计，应该首先建立地区土性参数的概率模型。作为反映土性指标自相关特性的相关距离，研究其区域分布特性，建立其概率分布模型是必要的。本文收集了西安黄土的176个钻孔CPT数据，利用其端阻值qc作为样本，采用递推空间法计算了各层西安黄土的相关距离。研究了计算结果的统计特性，并对其均值进行了单侧置信区间估计，提出了各层西安黄土相关距离的代表值。建立了西安各层黄土相关距离的概率模型，对模型参数进行了估计，采用皮尔逊-卡方检验法对模型进行了拟合优度检验，检验结果认为其符合Beta分布。

STATISTICAL DISTRIBUTION CHARACTERISTICS OF CORRELATION DISTANCE OF XIAN LOESS

Determination of soil probability model parameters is the foundation of reliability design in geotechnical engineering. In order to promote the reliability design of geotechnical engineering, regional probability model of soil index should be established firstly. As a reflection of autocorrelation characteristic of soil index-correlation distance, it's necessary to study its regional distribution characteristics and establish the probability distribution model. This paper collects 176 drilling CPT data of Xi'an loess. It uses the resistance value qc as sample and calculates the correlation distance of Xi'an loess by spatial recursive method. It analyzes the statistical characteristics, estimates the unilateral confidence interval of average value. Representative value of Xi'an loess correlation distance in each layer is put forward. Probabilistic model of Xi'an loess correlation distance is established. The model parameters are estimated. The goodness- of -fit test on the model is conducted using the Pearson chi-square method. The test results show that the model complies with the Beta distribution.