MANDREL FOR FORMING AN AGGREGATE PIER, AND AGGREGATE PIER COMPACTING SYSTEM AND METHOD

• US 20170058477A1
• Filed: 08/11/2016
• Published: 03/02/2017
• Est. Priority Date: 09/01/2015
• Status: Active Grant

• Current Assignee: Bahman Niroumand
• Original Assignee: Bahman Niroumand
• Inventors: Niroumand, Bahman
• Granted Patent: US 9,915,051 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: E02D 27/14 Pile framings , i.e. piles assembled to form the substructure
• CPC Class Codes: E02D 27/18 Foundations formed by making use of caissons
• CPC Class Codes: E02D 27/26 Compacting soil locally before forming foundations; Construction of foundation structures by forcing binding substances into gravel fillings consolidating foundation soil in general E02D3/02 - E02D3/12; for piles E02D5/02, E02D5/46
• CPC Class Codes: E02D 3/02 Improving by compacting E02D3/11 takes precedence; compacting soil locally before or while forming foundations E02D27/26, E02D27/28
• CPC Class Codes: E02D 3/08 by inserting stones or lost bodies, e.g. compaction piles sand drains for soil compaction E02D3/10; stressing soil while forming foundations E02D27/28
• CPC Class Codes: E02D 5/60 Piles with protecting cases
• CPC Class Codes: E02D 5/62 Compacting the soil at the footing or in or along a casing by forcing cement or like material through tubes

Abstract

An aggregate pier compacting system for forming a compacted aggregate pier (AP) at a target location includes a mandrel, a tamper device, and a finishing tamper device. The mandrel includes a casing for housing a drilling shaft (DS). An external vibratory hammer (EVH) repeatedly impacts a hammer element (HE) extending from the DS. The DS transfers the impact to a bore head to form a cavity at the target location. The DS is removed and the casing is filled with aggregate. The tamper device includes a compacting shaft. The EVH impacts a second HE extending from the compacting shaft and transfers the impact to a compaction head to form the compacted AP. The finishing tamper device includes a shaft. The EVH impacts a third HE extending from the shaft and transfers the impact to a finishing head compacting a top layer of the AP to form a finished AP.

Claims

1. A mandrel for forming an aggregate pier at a target location, the mandrel comprising:

a casing having a generally hollow cylindrical configuration for housing a drilling shaft; and

the drilling shaft comprising a first end and a second end, a generally cuboidal hammer element extending from the first end of the drilling shaft for receiving multiple impacts from an external vibratory hammer, the first end detachably attached to the casing via a locking system for transferring the impact to a bore head positioned at the second end of the drilling shaft for forming a cavity at the target location, wherein the drilling shaft is detached from the casing to fill the casing with aggregate, and wherein the aggregate filled casing forms the aggregate pier at the target location.

2. The mandrel of claim 1, wherein the aggregate pier is compacted by a tamper device comprising a compacting shaft, the compacting shaft comprising a first end and a second end, a generally cuboidal second hammer element extending from the first end of the compacting shaft for receiving multiple impacts from the external vibratory hammer and transferring the impact to a compaction head positioned at the second end of the compacting shaft for forming the compacted aggregated pier at the target location.

3. The mandrel of claim 2, wherein a top layer of the compacted aggregate pier is finely compacted by a finishing tamper device comprising a shaft, the shaft comprising a first end and a second end, a generally cuboidal third hammer element extending from the first end of the shaft for receiving multiple impact from the external vibratory hammer and transferring the impact to a finishing head positioned at the second end of the shaft for compacting the top layer of the compacted aggregate pier to form a finished aggregate pier at the target location.

4. The mandrel of claim 1, wherein the aggregate is a gravel material.

5. The mandrel of claim 1, wherein the bore head is of one of a conical configuration and a pyramidal configuration.

6. The mandrel of claim 1, wherein the bore head is configured in a wedge shape to bore through hard rock surfaces.

7. The mandrel of claim 1, wherein the target location is selected from a group consisting of a loose sandy soil, a clayey soil, a medium density soil, and a hard rock soil bed.

8. An aggregate pier compacting system for forming a compacted aggregate pier at a target location, the aggregate pier compacting system comprising:

(a) a mandrel for forming an aggregate pier at the target location comprising;

a casing having a generally hollow cylindrical configuration for housing a drilling shaft; and

the drilling shaft comprising a first end and a second end, a generally cuboidal hammer element extending from the first end of the drilling shaft for receiving multiple impacts from an external vibratory hammer, the first end detachably attached to the casing via a locking system for transferring the impact to a bore head positioned at the second end of the drilling shaft for forming a cavity at the target location, wherein the drilling shaft is detached from the casing to fill the casing with aggregate, and wherein the aggregate filled casing forms the aggregate pier at the target location;

(b) a tamper device for compacting the filled aggregate comprising a compacting shaft comprising a first end and a second end, a generally cuboidal second hammer element extending from the first end of the compacting shaft for receiving multiple impacts from the external vibratory hammer and transferring the impact to a compaction head positioned at the second end of the compacting shaft for forming the compacted aggregated pier at the target location; and

(c) a finishing tamper device comprising a shaft, the shaft comprising a first end and a second end, a generally cuboidal third hammer element extending from the first end of the shaft for receiving multiple impact from the external vibratory hammer and transferring the impact to a finishing head positioned at the second end of the shaft for compacting a top layer of the compacted aggregate pier to form a finished aggregate pier at the target location.

9. The aggregate pier compacting system of claim 8, wherein the bore head is of one of a conical configuration and a pyramidal configuration.

10. The aggregate pier compacting system of claim 8, wherein the bore head is configured in a wedge shape to bore through hard rock surfaces.

11. The aggregate pier compacting system of claim 8, wherein the compaction head is of one of a conical configuration and a pyramidal configuration.

12. The aggregate pier compacting system of claim 8, wherein the finishing head is of one of a flat bevel configuration and a cylindrical double bevel configuration.

13. The aggregate pier compacting system of claim 8, wherein the target location is selected from a group consisting of a loose sandy soil, a clayey soil, a medium density soil, and a hard rock soil bed.

14. A method for forming a compacted aggregate pier at a target location, the method comprising:

(a) Providing an aggregate pier compacting system comprising;

A mandrel comprising;

A casing having a generally hollow cylindrical configuration; and

a drilling shaft comprising a first end and a second end, a generally cuboidal hammer element extending from the first end of the drilling shaft, wherein the first end is detachably attached to the casing via a locking system, and wherein a bore head is positioned at the second end of the drilling shaft;

a tamper device comprising a compacting shaft comprising a first end and a second end, a generally cuboidal second hammer element extending from the first end of the compacting shaft, wherein a compaction head is positioned at the second end of the compacting shaft; and

a finishing tamper device comprising a shaft, the shaft comprising a first end and a second end, a generally cuboidal third hammer element extending from the first end of the shaft, wherein a finishing head is positioned at the second end of the shaft;

(b) Positioning the mandrel above the target location;

(c) Generating a cavity by driving the mandrel using an external vibratory hammer;

(d) Removing the drilling shaft from the casing of the mandrel positioned in the cavity;

(e) Filling the casing of the mandrel with aggregate at least once;

(f) Removing the casing from the cavity filled with aggregate;

(g) Compacting the aggregate filled cavity at least once using the tamper device; and

(h) Compacting a top layer of the compacted aggregate pier with the finishing tamper device to form a finished aggregate pier at the target location.

15. The method of claim 15, wherein the aggregate is a gravel material.

16. The method of claim 15, wherein the bore head is of one of a conical configuration and a pyramidal configuration.

17. The method of claim 15, wherein the bore head is configured in a wedge shape to bore through hard rock surfaces.

18. The method of claim 15, wherein the compaction head is of one of a conical configuration and a pyramidal configuration.

19. The method of claim 15, wherein the finishing head is of one of a flat bevel configuration and a cylindrical double bevel configuration.

20. The method of claim 15, wherein the target location is selected from a group consisting of a loose sandy soil, a clayey soil, a medium density soil, and a hard rock soil bed.