Drop hammer control device for marine standard penetration test and method thereof

Abstract

The invention discloses a drop hammer control device for a marine standard penetration test and a method thereof. The drop hammer control device for the marine standard penetration test comprises a drill rod, a wire rope, and a pilereing hammer connected with one end of the wire rope, and the other end of the wire rope is connected with a driving device. the drop hammer control device further comprises a wave detection module and a control module, wherein the wave detection module comprises an inclinometer and a gyro sensor, the inclinometer is used for measuring the tilt angle of a ship, the gyro sensor is used for measuring the angular velocity of the ship, and the tilt angle and the angular velocity of the ship are transmitted to the control module in real time. According to the data measured by the wave detection module, the control module calculates the heaving variation in the next step of the ship, and adjusts the momentum of the driving device to drive the pilereing hammer to achieve a drop distance meeting the standard requirement. By arranging the wave detection module and the control module, the heaving variation in the next stop of the ship can be predicted in real time, therefore the driving device can be controlled to adjust the momentum of the wire rope, the free fall of pilereing hammer with the accurate drop distance can be guaranteed, and an accurate standard penetration blow count can be obtained.

Description

technical field [0001] The invention relates to an in-situ test device and a control method for engineering sites, in particular to a drop hammer control device and method for offshore standard penetration tests. Background technique [0002] Standard Penetration Test (SPT for short) is a commonly used in-situ test method in engineering investigation, especially suitable for sandy soil layers where it is difficult to obtain undisturbed samples. The SPT test process is to use a 63.5kg core-piercing hammer to drop the hammer freely at a height of 76cm, first drive the standard penetrator into the soil for 15cm, and then record the hammering number (N) of 30cm into the soil , according to the standard penetration number (N) of 30cm to judge the physical and mechanical properties of the soil. Through SPT, the relative density Dr of sandy soil can be determined indirectly, and the internal friction angle of soil can be evaluated and the undrained shear strength of cohesive soi...

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Problems solved by technology

[0004] A water exploration solution is also disclosed in the prior art. For example, the Chinese utility model patent No. 201120385192.4 discloses a "power head for a wave compensation separated hydraulic drilling rig". It adopts separate soft connection between power and control system, and has the function of wave compensation, which is suitable for shallow sea engineering exploration, but does not involve standard penetration fall distance control

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