Combined test method for testing strength and rheological properties of marine ultra-soft soil

Abstract

The invention discloses a combined test method for testing strength and rheological properties of marine ultra-soft soil, and belongs to the technical field of offshore engineering. The method is based on the advantages of a full-flow penetrometer in the aspect of strength test and the advantages of a rheometer in the aspect of shear strain rate test, the method comprises the following steps of: respectively testing a marine ultra-soft soil sample by adopting two types of devices; and calibrating a strength result measured by the rheological test part by taking a strength value measured by thestrength test part under the reference shear strain rate as the standard strength, and correcting the strength curve measured by the rheological test part according to the calibration result, therebyobtaining the strength and rheological property parameters of the marine ultra-soft soil. The test method provided by the invention has the characteristics of the reliable strength test result (whichcan be as low as 0.001 kPa), the wide shear strain rate test range (which can exceed 100s-1 or is less than 0.001s-1), the rich test parameters (undrained shear strength, sensitivity, yield stress and viscosity) and the like, and technical reference is provided for the mechanical property test of the marine ultra-soft soil in offshore engineering.

Description

technical field [0001] The invention belongs to the technical field of offshore engineering, and relates to a test method for testing the mechanical properties of soft soil indoors, in particular to a combined test method for testing the strength and rheological properties of marine ultra-soft soil. Background technique [0002] In recent years, with the increasing scarcity of land space and energy, the pace of human development and utilization of the ocean has gradually accelerated. In my country's offshore tidal reclamation projects and seabed energy exploitation projects, engineering problems related to marine ultra-soft soils are often encountered, such as: reinforcement problems of dredging and dredging silt soil, pipeline laying problems of soft clay on the seabed surface, oil and gas platforms The stability of the submarine mooring foundation in the seabed soil, etc. Therefore, to reliably evaluate the strength and rheological properties of the marine supersoft soil, a...

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Problems solved by technology

Marine supersoft soils usually show the characteristics of extremely high water content (water content exceeding the liquid limit of the soil, even reaching more than 3 times the liquid limit), extremely low strength (less than 5kPa, even as low as 0.01kPa), and large void ratio. , which makes it impossible for traditional geotechnical testing methods to reliably and comprehensively test its mechanical properties. As a result, sampling and sample preparation are difficult, and the shear strain rate of fluid marine supersoft soils varies too much. It is urgent to propose a method for comprehensive testing and evaluation of mechanical properties of marine supersoft soils, especially for Testing of soil strength and rheological parameters widely used in engineering

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