Collapsible Loess Area Of ​​deep Foundation And Slope Of Bolt Support Force Performance Of Applied Research

Nowadays, anchor is one of the most chosen as a member of supporting structure in Civil Engineering. The stress law of anchor various with different soil and different embedding angle. The author tries to discuss the stress law and best embedding angle of anchor when it is used in Loess. In order to get specific data, series of tests for stress law on anchor are performed within the lab, with Loess as the supporting media. Included are tensile and pressure anchors in different embedding angles: 300 45 0 600 . The findings indicate: the stress law of anchor is similar to some other supporting media. And theoretically, a calculating formula for best embedding angle a is deduced, which is simplified as a ~60O ?is the internal friction angle). Meanwhile, the golden mean principle for variation of shearing force along the anchor is brought forward, according to the experimental data. The Loess collapsibility in Lanzhou is also discussed exploratively in this paper. Testing to the samples form some projects shows the collapsible coefficient of high-grade Loess in Lanzhou doesn抰 agree with the law that collapsible coefficient should decrease with the depth downward. In order to find out the reasons, the soil sample are analyzed in chemical component and structure, which demonstrates the Na2CO~ content is 4. 3 times more than that of ordinary soil in China. The new datum can not be verified definitely for lack of sufficient tests. However, it is deserved to be taken seriously by relevant researchers.