Device for measuring strength and strain softening parameters of saturated clay sample based on full-flow penetration

Patent metadata

Field	Value
Publication number	US-10816448-B2
Application number	US-201916652791-A
Country	US
Kind code	B2
Filing date	Aug 31, 2019
Priority date	Sep 4, 2018
Publication date	Oct 27, 2020
Grant date	Oct 27, 2020

Abstract

A device for measuring strength and strain softening parameters of a saturated clay sample based on full-flow penetration belongs to the technical field of geotechnical, geological and environmental research. The device mainly comprises two parts: an overlying pressure loading system and a full-flow penetration system. The present invention mainly aims at the problem of incomplete backflow of the soil in the measurement of soil strength and strain softening parameters with a full-flow penetrometer for saturated clay, and applies the working principle of a traditional consolidometer to vertically pressurize a soil sample to ensure the backflow of the soil, thereby improving the applicability of the full-flow penetrometer in the measurement aspect of the soil strength and the strain softening parameters and having important practical value for test research and marine engineering design.

First claim

The invention claimed is:

1. A device for measuring strength and strain softening parameters of a saturated clay sample based on full-flow penetration, wherein the device for measuring strength and strain softening parameters of a saturated clay sample comprises two parts: an overlying pressure loading system I and a full-flow penetration system II;
the overlying pressure loading system I comprises a test workbench, a lever pressure conversion device, a load weight, an annular pressurizing frame, a force transmission shaft, an annular steel ring, a full-flow penetrometer, a cylindrical rigid box, a rigid box base, a rigid box side wall, a rigid box connection flange, a rigid box movable top cover, a top cover positioning rod, a sealable hole, a fixing screw, a drainage valve, geotextile, filter paper and porous stone;
the test workbench is placed on flat ground; the load weight and a tail weight are configured to be leveled by adjusting a front end of a lever; the lever pressure conversion device is installed on a table surface of the test workbench; and the load weight is connected to the lever pressure conversion device;
the cylindrical rigid box is placed on a top surface of the lever pressure conversion device; a cylindrical soil sample is placed inside the cylindrical rigid box; a bottom of the cylindrical rigid box and the rigid box base are connected by the rigid box connecting flange; the rigid box connecting flange is fixed to the rigid box base by the fixing screw on the rigid box connecting flange; the rigid box base is communicated with a drainage channel and communication between the rigid box base and the drainage channel is configured to be controlled by the drainage valve; the drainage valve is configured to control soil drainage conditions in a pressurization process; a top of the cylindrical rigid box is provided with the rigid box movable top cover; the rigid box movable top cover is provided with the sealable hole and the top cover positioning rod for penetrating through the full-flow penetrometer; the positioning rod is used to fix installation and facilitate removal of the annular steel ring and the rigid box movable cover; the sealable hole is configured to prevent the soil sample from being extruded during penetration and extraction of the full-flow penetrometer; the annular steel ring is fixed to the rigid box movable top cover; the annular pressurizing frame and the annular steel ring are connected by four steel rods; the lever pressure conversion device is connected with the annular pressurizing frame through the force transmission shaft; two ends of the annular pressurizing frame are provided with through holes for the force transmission shaft to pass through, and a middle of the annular pressurizing frame is provided with through holes corresponding to the sealable hole and the top cover positioning rod of the full-flow penetrometer; the filter paper, the geotextile and the porous stone are respectively laid on a top and a bottom of cylindrical soil sample from inside to outside; the rigid box movable top cover is located on the porous stone on top of the cylindrical soil sample; the full-flow penetrometer and the cylindrical rigid box are assembled; a weight of the load weight is adjustable; and pressure is applied to the soil sample in the rigid box through the annular pressurizing frame;
the full-flow penetration system II comprises the full-flow penetrometer, a loading and data collecting system and a full-flow penetrometer bracket; the full-flow penetrometer bracket is placed on a top surface of the test workbench; a shaft of the full-flow penetrometer is connected with a loading motor on the full-flow penetrometer bracket; a load cell is installed on a top end of a probe to measure penetration resistance of the probe during cyclic penetration and extraction; the loading and data collecting system is in electrical communication with the loading motor, the load cell, a power supply for power distribution and voltage stabilization, and a computer; the loading motor is configured to control the penetration and extraction speed of the full-flow penetrometer; a signal of the load cell is configured to be collected in a test process; and the device is configured to estimate the soil sample strength based on a measured pressure signal of the load cell.

Assignees

• Univ Dalian Tech

Inventors

• Yu Long
• Han Yunrui
• Yang Qing
• Wang Zhongtao

Classifications

• G01N3/40

  Investigating hardness or rebound hardness · CPC title

• E02D1/025

  combined with sampling · CPC title

• G01N3/48 Primary

  by performing impressions under impulsive load by indentors, e.g. falling ball (G01N3/54 takes precedence) · CPC title

• G01N2203/0284

  Bulk material, e.g. powders · CPC title

• G01N2203/0019

  Compressive · CPC title