Drop mass compaction of soil

Abstract

A soil compaction apparatus includes a drop mass soil compactor having a mass and a lift assembly that repeatedly raises the mass above a soil surface and then drops it to apply impacts to the soil surface. The apparatus also has a sensor arranged to provide periodic indications of one or more instantaneous properties of the soil. The apparatus also includes a controller that received a signal from the sensor and controls the lift assembly to attain desired, pre-programmed soil properties based on a number of impacts, energy imparted to the soil at each impact or frequency if impacts of the mass.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of International Application No. PCT / IB2003 / 002578, filed Jul. 1, 2003, which was published in the English language on Jan. 8, 2004, under International Publication No. WO 2004 / 003301 A1, and the disclosure of which is incorporated herein by reference.BACKGROUND OF THE INVENTION [0002] This invention relates to methods and apparatus for achieving drop mass soil compaction and for monitoring soil properties. [0003] There are numerous applications where it is necessary to compact a relatively small area of soil but where the use of conventional soil compaction machinery, typically employing rollers of one type or another, is inappropriate. One important example is in the compaction of soil adjacent bridge abutments, where limited space makes it impossible to compact with conventional large rollers or other machines. Another example is in the compaction of soil in relatively narrow trenches for pipes, str...

AI Technical Summary

Benefits of technology

"The present invention provides a method and apparatus for compacting soil by repeatedly raising a mass above the soil surface and then dropping it to apply impacts to the soil surface. The method and apparatus allow for the control of impact parameters, such as the number of impacts, energy imparted, and frequency of impacts, to achieve desired properties in the soil. The apparatus includes a sensor to provide indications of soil properties, and a controller to automatically adjust impact parameters based on the sensor indications. The apparatus can also be used to measure physical properties of soil on a site."

Problems solved by technology

There are numerous applications where it is necessary to compact a relatively small area of soil but where the use of conventional soil compaction machinery, typically employing rollers of one type or another, is inappropriate.

One important example is in the compaction of soil adjacent bridge abutments, where limited space makes it impossible to compact with conventional large rollers or other machines.

Although small vibratory rollers and impactors are available and are widely used in such applications, the level of soil compaction and the depth of compaction influence which can be achieved with such devices is limited.

The result is often that undue settlement and or structural failure can take place after a relatively short period of time.

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