Saturated sand liquefaction detection method based on standard penetration test

Abstract

The invention relates to a saturated sand liquefaction detection method based on a standard penetration test. The method comprises the following steps of: establishing a saturated sand liquefaction detection model related to saturated sand burial depth, underground water level depth, fine particle content, earthquake magnitude and earthquake peak acceleration, and obtaining a critical standard penetration number; and carrying out saturated sand liquefaction discrimination by utilizing the critical standard penetration number and a corrected actually measured standard penetration number. Compared with the prior art, the method has the advantages that the defects that a liquefaction discrimination formula in a building anti-seismic design specification (GB 50011-2010) is inclined to risk ina saturated sand shallow layer and is inclined to conservative in a saturated sand deep layer are overcome, so that a detection result is more accurate; liquefaction discrimination of soil bodies withvarious burial depths and fine particle contents can be met under various intensities, and the method has wide applicability; and the discrimination formula is simple in form, comprehensive in consideration and suitable for being used in actual engineering; and based on a foreign liquefaction database, the earthquake site is more, the data size is large, good representativeness is achieved, and popularization is easy.

Description

technical field [0001] The invention relates to the field of judging the liquefaction of saturated sandy soil in seismic sites, in particular to a method for detecting liquefaction of saturated sandy soil based on a standard penetration test. Background technique [0002] The liquefaction of saturated sand has always been one of the main reasons for the damage of building foundations and superstructures after earthquake disasters, causing huge loss of life safety and property, which may lead to quicksand, foundation subsidence, and soil lateral movement in earthquake sites. In view of my country's complex engineering geology and hydrogeology conditions and the risk of potential earthquakes, the study of the mechanism of saturated sand liquefaction, the development of liquefaction discrimination methods and the corresponding seismic fortification technology have received unanimous attention from both academic and engineering circles. It is of great significance to judge the li...

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Problems solved by technology

[0009] In the formula, CSR is the cyclic stress ratio (Cyclic Stress Ratio), CRR is the cyclic resistance ratio (Cyclic Resistance Ratio), MSF is the magnitude correction factor, FS is the safety factor, if FS>1, it is judged as non-liquefied, otherwise, it is judged as Liquefaction, which is based on the standard penetration blow count of the corrected measured standard penetration blow count (N 1 ) 60 , this discriminant method is quite different from the domestic normative method

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