US20050081465A1

US20050081465A1 - Masonry wall tension device and method for installing same

Info

Publication number: US20050081465A1
Application number: US10/685,945
Authority: US
Inventors: Harvel Crumley
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-10-15
Filing date: 2003-10-15
Publication date: 2005-04-21
Also published as: US20090094916A1

Abstract

Masonry walls of buildings supported on concrete foundations are strengthened against destructive wind and seismic forces by spaced elongated members inserted inside the hollow masonry walls. The spaced elongated members are secured to the continuous masonry bond beam and the foundation. Tension means at the top of the masonry wall make the elongated members taut creating a continuous tension load path from bond beam to the foundation.

Description

CROSS-REFERENCE TO RELATED APPLICATION

Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

REFERENCE TO A MICROFICHE APPENDIX

Not Applicable

BACKGROUND OF THE INVENTION

Masonry structures predominate in residential and light commercial construction. In order to provide protection from strong winds, tornadoes, hurricanes, and seismic activity, builders reinforce installed masonry walls by filling cells of the masonry wall with concrete and steel bars at selected locations. The number of the reinforced cells, the quantity of concrete and the number of bars used vary depending on the severity of the wind and the geometry of the structure.
Masonry structures can also be strengthened during installation. Masonry units are laid over the reinforcing bars so that the bars are in the center of the cell within the masonry unit. Builders install additional reinforcing bars inside the voids and pour concrete around the bars. After building the wall, builders construct a masonry bond beam on top of the masonry wall to bond all of the walls together.
However, this method for strengthening masonry walls suffers from various problems. When builders fill the cells of a masonry wall with steel bars and concrete, they do not tie or connect the wall with the concrete foundation or the masonry bond beam. As a result, the masonry wall tends to vibrate back and forth during strong seismic movements or strong winds.
Additionally, filling the cells or voids of the masonry units, strengthens the masonry units around these cells, but does not strengthen the adjacent units. As a result, the masonry units are not strongly bonded together. Therefore the masonry wall tends to be vulnerable to strong winds or seismic forces. In particular, the wall is vulnerable at the masonry units, which are further from the reinforced cells.
Another method of strengthening buildings against winds and seismic forces is disclosed in applicant's U.S. Pat. No. 6,014,843. Wood framed walls of buildings are strengthened by spaced lengths of vertical wire rope having enlarged bulbous portions swaged on each end. Other lengths of wire rope form a cross brace connecting each story of a building with its foundation. The cross brace wire ropes terminate in bulbous portions connected to attachments therein. However, the method and system described above are applicable only to wood framed walls.
Consequently, in light of the previous problems, there is a critical need for a structural tie-down system that provides for uplift, shear, and overturning loads that is cost efficient and installed after the foundation is laid and the masonry units have been placed. The present invention meets and exceeds these needs.
It is an object of this invention to provide for a device for tensioning a masonry wall.
It is another object of the present invention to provide a device for placing the masonry walls under compression to prevent them from vibrating or moving during strong winds or some seismic movement.
It is still another object of the present invention to provide a device for tying a masonry bond beam on top of masonry walls with the concrete foundation that support these walls.
It is a further object of the present invention to provide for a method for placing masonry walls under compression after building these walls.
Yet another object of the present invention is to provide a method for installing a tensioning device in a hollow masonry wall to compress it.

BRIEF SUMMARY OF THE INVENTION

The present invention relates to a novel device for placing masonry structures under compression and a method for installing the device in the masonry structure. The tie-down system can be installed after the foundation and masonry walls are completed or before installing the walls. The tie-down system creates a continuous tension path from the masonry bond beam on the top of the masonry wall to the foundation at the bottom. An elongated member, preferably in the form of a wire rope, is used for developing tension in a hollow masonry wall. The elongated member has a length greater than a length of the masonry wall to be tensioned. The elongated member includes lower and upper end portions.
A method for installing the elongated member into the masonry structure after building the masonry walls includes the steps of removing knock-out portions of the hollow masonry units located adjacent the bottom of the masonry wall and exposing a surface portion of the foundation below the masonry wall and drilling an elongated bore into the exposed surface portion of the foundation. Providing a passageway through the bond beam by either drilling a bore therein or drilling a bore and placing a sleeve inside the bore and placing an adhesive inside the foundation bore. The elongated member is vertically inserted inside the hollow masonry units of the wall through the passageway to secure the lower end portion of the elongated member inside the foundation bore. After the adhesive is cured, a washer and nut are placed over the threaded upper end of the elongated member that extends through the passageway beyond the bond beam. The nut is tightened to tension the elongated member and place the masonry wall under compression.
The elongated member can also be installed during the building of the masonry structure. A bore is drilled into a concrete foundation, and an adhesive is placed inside the bore. A first row of hollow masonry units is laid on the foundation. A second row of the masonry units is laid on the first row and vertically aligned to alternate holes of the vertically adjacent masonry units to create a continuous passageway with the bore in the foundation. A second row of the masonry units is laid on the first row and vertically aligned to alternate holes of the vertically adjacent masonry units to create a continuous passageway with the bore in the foundation. The elongated member is then inserted into the bore through the hollow masonry unit. Additional rows of the units are laid until the desired wall height is achieved. The bond beam is poured on top of the wall with a sleeve disposed around the upper end portion of the elongated member to keep concrete away from the passageway of the elongated member. A washer and a nut are threadedly engaged with the upper end portion of the elongated, member and tightened to tension the elongated member.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The novel features which are believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawings, in which:
FIG. 1 is a front elevational view of a one-story masonry building structure showing the spaced elongated tension members according to the present invention for tensioning the masonry wall;
FIG. 2 is a cross-sectional view showing the lower portion of the member of FIG. 1 installed in a masonry building;
FIG. 3 is an enlarged cross-section of the upper end portion of one embodiment of the tension member placed inside a passageway in the bond beam;
FIG. 4 shows another embodiment of the upper portion of the invention;
FIG. 5 shows a further embodiment of the upper portion of the invention;
FIG. 6 shows another embodiment of the upper portion of the invention;
FIG. 7 illustrates an upper plate employed in FIG. 6;
FIG. 8 illustrates a two-story application of the present invention;
FIG. 9 illustrates another embodiment of the upper portion of the invention; and
FIG. 10 illustrates a combined nut and sleeve employed in FIG. 8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention may be best understood by reference to the attached drawings wherein FIG. 1 shows the usage of the invention, and the remaining FIGS. Illustrate various embodiments of the tension device.
In FIG. 1 a partial section of a masonry building is shown at numeral 10. The building includes at least two masonry walls 12 supported on a concrete foundation 13. A continuous bond beam 11 is laid on top of the masonry walls 12 to strengthen the walls. Each of the masonry walls 12 includes a plurality of vertical hollow wall sections 14 having a number of hollow masonry units 15, laid over each other.
FIG. 1 shows a tensioning device, an elongated member 18, installed in a hollow masonry wall 12. The member 18 extends through and above the bond beam 11 located at the top of the masonry wall 12 and is secured to a foundation 13, by securing means such as epoxy resin adhesive. The member 18 ties the masonry wall 12 with the bond beam 11 and the concrete foundation 13 to compress the masonry wall 12 between the bond beam 11 and the foundation to prevent the wall 12 from vibrating or moving during strong winds or seismic movement.
A member 18 is disposed inside each vertical hollow wall section 14, which includes a plurality of hollow masonry units 15 laid on top of each other forming a continuous vertical hole 32 throughout the vertical wall section 14. In order to connected the masonry wall 12 with the bond beam 11 and the foundation 13, the upper end portion 20 of the elongated member 18 is secured to the bond beam 11, while the lower end portion 19 of the elongated member 18 is attached to the foundation 13. The upper end portion 20 is secured to the bond beam 11 by a fastener or a washer 25 and a nut 26, shown in FIG. 2. An adhesive, such as epoxy resin 30 shown in FIG. 2, attaches the lower end portion 19 to the foundation 13.
FIG. 2 shows details of the elongated tension member 18, formed principally of wire rope. The lower end portion 19 has a lower stud 22 swaged into integral lower bulbous element 23. The lower stud 22 is secured to the foundation bore 16 by an adhesive or an epoxy resin 30 placed inside the bore 16. The lower end portion 19 can also be a threaded stud 33, as shown in FIG. 3, and secured to the foundation bore 16 by means known in the art.
In FIG. 3, the upper end portion 20 of the elongated tension member 18 includes upper stud portion 21, swaged inside the integral upper bulbous element 24. The upper end portion 20 passes through a sleeve 31 disposed inside a passageway 17 inside the continuous masonry bond beam 11.
The upper end portion 20 of the element 18 extends through and above the bond beam 11.
In order to install the member 18 through the masonry wall 12 after installing the wall 12, a passageway 17 is drilled through the bond beam 11 to allow the upper end portion to pass therethrough. When building the masonry wall 12, a sleeve 31 can be added to enclose upper portion 20 and extend a passageway 17 upwardly. A washer 25 and a nut 26 are threadedly engaged to the upper stud 21. Tightening the nut 26 tensions the member 18 and places the masonry wall under compression.
The member 18 may be constructed of a rebar 28 as shown in FIG. 4. The rebar 28 has an upper end portion 35 having threads 29 and a lower end portion 36. The upper end portion 35 terminates with the welded upper stud 39 extending beyond the bond beam 11. The upper end portion 35 is secured to the bond beam by a washer 38 and a nut 37 to tension the rebar 28 when tightening the nut 37. The member 18 can be made of any substantially non-stretchable bar. A sleeve 33 may be provided as before to create passageway 34. A welded, threaded lower stud 39′ having threads 29′ may be provided if desired.
Alternatively, the tension member may be a long threaded rod or bolt 40. The upper end portion 42 includes a threaded stud 39′ as shown in FIG. 5. The lower portion 41 may be threaded as shown or have some other irregularity or bulbous connector affixed thereto, as with member 18. The upper end portion 42, which includes welded upper stud 39, is secured to the bond beam 11 by a fastener or a washer 43 and a nut 44. Sleeve 47 and passageway 46 are as before.
In FIG. 6, another embodiment of the upper portion of the tension member 18 illustrated in FIG. 3 is shown at 48. The apparatus is substantially identical to the upper end portion 20 illustrated in FIG. 3 with additional features. In lieu of washer 25, plate 50 is provided with sufficient width to provide for flanges 51 over the upper edges 55 of bond beam 11. Subtending hook members having loop ends 53 carry horizontal rebars 54 to provide for additional strength. Sleeve 49 may terminate at the lower surface of bond beam or may continue through passageway 17 as shown in FIG. 3.
As shown in FIG. 7, hook members 52 may be spacedly staggered if desired in the circumstances.
FIG. 8 illustrates a two-story application of the invention with the upper portion 56 illustrated in FIGS. 9-10. The upper tension device 18′ includes the tension member 57 formed of wire rope and is preferably threadedly anchored over and to the projecting portion of upper stud 21 of upper portion 48 as illustrated in FIG. 6. The bulbous element 58 in this application has the wire rope 57 swaged into it as before. Element 58 is integral to an upper threaded stud portion 59 attached atop two plates 60 via washer 61 and nut 62. Sleeve 63 is integral with nut 62 and passes through passageway 64 (FIG. 9).
The embodiment of FIGS. 8-10 provides for integral female threads 65 for engagement with threaded stud portion 59. The large number of engaged threads 65 provides for greater strength of engagement that may be desired in the circumstances. In addition, the lower end of threads 65 engages the stud 59 and allow for a shorter tension element to be used.
In the utilization of the invention as shown in FIG. 8 the upper portion of the tension device illustrated in FIG. 3-7 may be used with the upper end of FIG. 6 preferred.
Also disclosed are methods for installing the elongated member 18 inside the masonry building 10. The method includes removing knock-out portions 67, shown in FIG. 1 from vertical hollow wall sections 14, thereby exposing a surface portion of the concrete foundation 13. A foundation bore 16 is drilled in the foundation 13 and an adhesive 30 is placed inside the bore 16. Tension member 18 is inserted vertically through sleeve 31 in the continuous masonry bond beam 11 and through hollow masonry units into the foundation bore 16. The lower end portion 19 of the member 18 is attached to the foundation 13 by an epoxy resin 30. Tensioning means or a nut 26 and a washer 25 are threadedly engaged with the upper end portion 20 of the elongated member 18. The nut 26 is then tightened to cause the member 18 to be taut and thereby compress masonry wall 12.
The elongated member 18 can also be installed while building the masonry walls 12. Spaced bores 16 are drilled into the concrete foundation 13. An adhesive 30 is placed into the foundation bores 16. A first row of hollow masonry units 15 is laid on the foundation 13. A second row of hollow masonry units 15 is laid on the first row and vertically aligned to alternate holes of the vertically adjacent masonry units 15, thus creating a continuous passageway with the plurality of spaced bores 16 in the concrete foundation 13. Pluralities of member 18 are then inserted into the bores 16 through the hollow masonry units 15. Each member 18 has a height greater than the height of the masonry wall 12. Additional rows of masonry units 15 are laid until a predetermined height of the masonry wall 12 is achieved. A masonry bond beam 11 is poured on top of the masonry wall 12 with the sleeves 31 disposed around the upper end portion 20 of the members 18 to prevent concrete from impeding the passage of the members 18. The upper end portion 20 of the member 18 is tensioned to compress the masonry wall 12 by threadedly engaging a washer 25 and a nut 26 with the upper end portion 20 of the members 18. The nut 26 is tightened to tension the members 18, and compress the masonry walls 12. Concrete 66 is poured when appropriate.
While the invention has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention.

Claims

1. A tension device for use in a masonry building which has a concrete foundation including at least one masonry wall supported on and attached in a bore in the employing foundation and a continuous masonry bond beam formed at the upper portion, each masonry wall formed of a plurality of side by side vertical hollow wall sections, said tension device comprising an elongated member positioned inside a hollow of each wall section, said elongated member having upper and lower portions extending into and secured to such foundation and extending through such masonry bond beam, and means for selectively tensioning said elongated member for causing such at least one wall section to be in compression.

2. The tension device as defined in claim 1 wherein said upper portion of said elongated member includes a threaded upper stud.

3. The tension device as defined in claim 2 wherein said threaded upper stud passes through a passageway in a masonry bond beam and extends above it, and said means for tensioning said elongated member includes a nut, said nut being threaded on said upper stud and tightened to tension said elongated member between such bond beam and such foundation.

4. The tension device as defined in claim 1 further including threads formed on said lower portion of elongate member and adhesive disposed within such bore for securing said lower portion firmly inside such bore.

5. The tension device as defined in claim 1 wherein said elongated member is substantially rigid.

6. The tension device as defined in claim 1 wherein said elongated member includes a length of wire rope having opposite ends.

7. The tension device as defined in claim 6 further including a bulbous element attached at one said end of said wire rope and integral one said end of said wire rope.

8. The tension device as defined in claim 7 further including another bulbous element attached to another said end of said wire rope, said another bulbous element being adapted to be secured to such foundation.

9. The tension device as defined in claim 7 wherein said threaded upper end stud passes through said bulbous element and extends through a passageway in the masonry bond beam thereabove, said means for tensioning including a threaded nut threadedly engaged with said upper threaded end stud for tensioning said wire rope, and a washer surrounding said upper threaded end stud and sandwiched between said nut and the masonry bond beam.

10. The tension device as defined in claim 1 wherein said elongated member is a threaded rod.

11. The tension device as defined in claim 1 wherein said elongated member is a rebar, said rebar including threaded upper and lower end studs, said threaded upper and lower end studs being welded to said rebar.

12. The tension device as defined in claim 1 wherein said elongated member is a rebar, said rebar including threaded upper and lower end studs, said threaded upper and lower end studs being welded to said rebar.

13. The tension device as defined in claim 1 wherein said elongated member is substantially non-stretchable.

14. In a masonry building including a concrete foundation, a plurality of masonry walls supported on and attached to the foundation, and a continuous masonry bond beam formed at the upper portion of the plurality of masonry walls, the plurality of masonry walls comprising a plurality of side by side vertical hollow wall sections, at least one elongated member being positioned inside each of the masonry walls, each said elongated member extending into and secured to the foundation and extending through the masonry bond beam, and means for tensioning each said elongated member a predetermined amount causing each of the masonry walls to be in compression.

15. In the building of claim 14 wherein each said elongated member includes threaded upper studs.

16. In the building of claim 15 wherein said upper threaded stud of each said elongated member passes through a passageway in the masonry bond beam and extends above it, said means for tensioning each said elongated member including a nut, each said nut being threaded on said upper stud and tightened to tension each said elongated member.

17. In the building of claim 15 wherein said lower stud of each said elongated member is adapted to be secured to the foundation.

18. A method for tensioning a masonry wall having a plurality of sections each formed of vertically aligned hollow masonry blocks creating a continuous vertically disposed passageway supported on a concrete foundation, comprising the steps of:

A. drilling a plurality of spaced bores into the concrete foundation below each passageway;

B. inserting a plurality of elongated tension members, each having upper and lower end portions and having a predetermined length greater than the height of the masonry wall to be tensioned by the elongated member inside each passageway;

C. securing the lower ends of each elongated member into a respective bore in the foundation;

D. securing the upper end of each elongated ember to an upper portion of respective section; and

E. tensioning the upper end portion of the plurality of elongated member to an upper portion of respective section;

19. The method of claim 18 wherein step D includes the steps of:

F. positioning the masonry bond beam on top of the masonry wall;

G. forming a vertically disposed passageway through a bond beam;

H. positioning the upper end of a tension member through the passageway formed in step G;

I. installing a sleeve around the upper portion of the tension member and downwardly through the passageway of step G; and

J. pouring concrete into the masonry bond beam and around the sleeve installed in step 1.

20. The method of claim 18 wherein step E includes the steps of:

F. placing a washer and a nut over the upper end portion of the elongated member that extends through the passageway passing through the masonry bond beam; and

G. tightening the nut to tension the elongated member and place the masonry wall under compression.

21. A method for tensioning a masonry wall in a masonry building including a concrete foundation, the masonry wall supported on and attached to the foundation, and a continuous masonry bond beam formed at the upper portion of the masonry wall, the masonry wall including a plurality of vertical hollow wall sections, the hollow wall sections including a plurality of hollow masonry units, comprising the steps of:

A. accessing the interior of the hollow masonry units located adjacent the bottom of the masonry wall to expose a surface portion of the foundation below the masonry wall;

B. drilling an elongated bore into the exposed surface portion of the foundation;

C. providing a vertical passageway through the bond beam;

D. vertically inserting a lower end of elongated member having a predetermined length greater than a height of the masonry wall inside the hollow masonry units;

E. securing the lower end of the elongated member to the foundation; and

F. tensioning the elongated member to compress the masonry wall.

22. The method of claim 20 wherein step F includes the steps of:

G. placing a washer and nut over the threaded upper end of the elongated member that extends through the passageway through the masonry bond beam; and

H. tightening the nut to tension the elongated member and place the masonry wall under compression.

23. A tension device for use in a two-story building which has a roof and a concrete foundation including at least one first-story masonry wall supported on and attached in a bore in the foundation employing a continuous masonry bond beam having a vertical passageway therethrough formed at the upper portion of each masonry wall formed of a plurality of side by side vertical hollow wall sections, said tension device comprising an elongated member located inside a hollow of each wall section, said elongated member having a lower portion having top and bottom end portions extending into and secured to such foundation and extending vertically upwardly through the passageway in the masonry bond beam and an upper portion having top and bottom end portions attached to said top end portion of said lower portion of said elongated member and extending vertically to the roof and attached thereto, and means for tensioning said elongated member for causing such masonry wall section to be in compression.

24. The tension device as defined in claim 23 wherein said means for tensioning said elongated member includes a first adjustment means attached to said top portion of said lower portion of said elongated member for tensioning said lower portion of said elongated member and a second adjustment means attached between said top portion of said upper portion of said elongated member and the roof of such building for tensioning said upper portion of said elongated member.