Apparatus, systems and methods for improved vertical structural supports
11821207 · 2023-11-21
Assignee
Inventors
- William Dean Priefert (Mt. Pleasant, TX, US)
- Rocky Christenberry (Mt. Vernon, TX, US)
- Tracy Metzger (Pittsburg, TX, US)
Cpc classification
International classification
E04C3/07
FIXED CONSTRUCTIONS
Abstract
Disclosed herein are various methods, systems, and devices relating to vertical structural supports, including acute Z-shaped piers and further including vertical structural features that provide additional structural support for various types of piers.
Claims
1. A vertical support structure comprising: (a) an elongate central strut; (b) a first flange coupled to a first side of the elongate central strut, wherein a first angle between the first flange and the elongate central strut is acute; (c) a second flange coupled to a second side of the elongate central strut, wherein a second angle between the second flange and the elongate central strut is acute; and (d) a shear center disposed at a geographical center of mass of the vertical support structure, wherein a lateral load is applied to the vertical support structure in the same direction of as a principle neutral axis, wherein the principal neutral axis is aligned with the shear center and the principal neutral axis being aligned with the direction of the lateral load.
2. The vertical support structure of claim 1, further comprising a first angled end segment extending from the first flange.
3. The vertical support structure of claim 2, further comprising a second angled end segment extending from the second flange.
4. The vertical support structure of claim 1, wherein the vertical support structure has a cross-sectional shape that is substantially Z-shaped.
5. The vertical support structure of claim 1, further comprising at least one rib defined in the elongate central strut.
6. The vertical support structure of claim 5, further comprising two ribs defined in the elongate central strut, the two ribs disposed between substantially straight sections of the elongate central strut.
7. A support structure comprising: (a) a central strut comprising at least one rib; (b) a first flange coupled at a first acute angle to a first side of the central strut; (c) a second flange coupled at a second acute angle to a second side of the central strut; and (d) a neutral axis disposed at a centerpoint of a mass of the support structure.
8. The support structure of claim 7, wherein the central strut, the first flange, and second flange form a Z-shaped cross-section.
9. The support structure of claim 7, wherein deflection only occurs in a direction of an applied lateral load.
10. The support structure of claim 7, wherein the central strut comprises a substantially straight portion interrupted by the at least one rib.
11. The support structure of claim 7, further comprising at least one attachment feature defined in the first flange.
12. The support structure of claim 11, wherein the at least one attachment feature comprises at least one opening.
13. A support structure comprising: (a) a central strut; (b) a first flange coupled at a first acute angle to a first side of the central strut; (c) a second flange coupled at a second acute angle to a second side of the central strut; and (d) a neutral axis disposed at a cross-sectional centerpoint of a mass of the support structure and oriented in an identical direction as an expected lateral load.
14. The support structure of claim 13, wherein the support structure comprises first and second ribs defined within the central strut.
15. The support structure of claim 14, wherein the first rib extends outward from the first side of the central strut and the second rib extends outward from the second side of the central strut.
16. The support structure of claim 13, wherein the central strut, the first flange, and second flange form a substantially Z-shaped cross-section.
17. The support structure of claim 13, further comprising at least one attachment feature defined in the first flange.
18. The support structure of claim 13, further comprising at least one rib defined in the first flange.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
(14)
(15)
(16)
(17)
(18)
(19)
(20)
(21)
(22)
(23)
(24)
(25)
(26)
(27)
(28)
(29)
(30)
(31)
(32)
(33)
(34)
DETAILED DESCRIPTION
(35) The various embodiments disclosed or contemplated herein relate to improved support beam embodiments. Further embodiments relate to roll form support beams. The various support structure embodiments can be used in a number of implementations, including in the solar industry.
(36) Amongst various processes for forming a structural shape, roll forming provides flexibility such that it allows the engineer to use her/his creativity to generate the perfect shape for the specific application it is designed for. In use, roll forming takes slit coil known as band and cold form the shape through a progressive set of specially designed rollers to achieve the shape desired.
(37) The various support structure embodiments disclosed herein provide an optimized shape that can achieve the 3 measurements for a solar pier (discussed below) yet reduce the amount of material used in comparison to a standard wide flange beam (such as the beam 10 as depicted in
(38) As discussed above, in the solar industry, large fields with tens or hundreds of acres of solar arrays are becoming commonplace, as is shown generally at 1 in
(39) The various implementations of the vertical support structures 20 disclosed or contemplated herein offer an economical and improved replacement for the known wide flange beam of
(40) Various known cross-sectional shapes have been used in a variety of solar and/or non-solar industrial applications, including the known wide flange beam 10 (as best shown in
(41) In contrast, neither of the traditional 90-degree Z shape pier 14 of
(42) One vertical support structure that addresses these shortcomings is the acute angled Z shape vertical support structure 20 depicted in
(43) These implementations eliminate the out of plane deflection failures that can occur in the known 90-degree Z shape pier 14 of
(44) Another acute Z-shaped pier 30 embodiment is depicted in
(45) In addition, the ribs 36 ensure that the pier 30 is not categorized as a “slender member” by the American Institute of Steel Construction (“AISC”) in the AISC Steel Construction Manual Sections 16.1-14 through 16.1-18. It is understood that any pier categorized as a slender member may be subject to a decreased load capacity rating per the AISC code. The ribs 36 in this specific embodiment result in the web 32 having three straight sections with the two ribs 36 disposed between the straight sections. As such, the ribs 36 increase the width/thickness ratio of the web 32, thereby ensuring that the pier 30 is not a slender member.
(46) Alternatively, each of the structural support features 36 defined or otherwise formed in the web 32 can be any known structural feature—such as, for example, a channel, protrusion, ridge, castellation, or offset—that provides additional structural support and/or width to the pier 30. In one embodiment as shown, the web 32 has two ribs 36. Alternatively, the web 32 can have one rib, or three or more ribs.
(47) Further, in this implementation as best shown in
(48) One specific example of another pier 40 according to a further embodiment in which the flanges 42 have a different configuration of openings 44 is depicted in
(49) Another embodiment is depicted in
Example
(50) Lateral load testing was performed on six acute Z-shaped piers according to one embodiment of the invention disclosed herein and on six standard wide flange beam piers. This Example is a summary of the load testing and analysis of the comparative performance of the acute Z-shaped pier vs. the standard wide flange beam piers. sections.
(51) The specific characteristics of the two types of piers are set forth in Table 1.
(52) TABLE-US-00001 TABLE 1 Test Pier Properties Acute Wide Property Z-Shaped Pier.sup.(1) Flange Beam.sup.(2) Depth (in.) 8.00 5.83 Width (in.) 4.69 3.94 Moment of Inertia (in.sup.4.) 20.5 14.9 Section Modulus (in.sup.3.) 5.12 5.10 Area (in.sup.2.) 2.14 2.52 Weight (lb/ft) 7.26 8.5 Yield Strength (psi) 50 50 .sup.(1)Data evaluated from CFS Property Calculation .sup.(2)AISC Steel Construction Manual, 14.sup.th Ed.
(53) A total of twelve (12) test piers (six acute Z-shaped piers and six standard wide flange piers) were installed vertically into the ground at the test area, with embedment depths of 5, 5.5 and 6 feet (two piers of each type to each depth). The piers all had at least 5 feet of reveal above grade (length of each pier above the ground). The piers were installed in one row with the strong axis aligned parallel to the row.
(54) Pier testing was completed in substantial conformance with ASTM D3966 for lateral testing, appropriately modified for solar piers. For the lateral load tests, horizontal loads were applied to the pier at a height above ground of 5-feet, using a bearing plate that loaded the flanges equally.
(55) Deflection was measured at two locations along the exposed portion of the pier using dial gauges. Loads were applied using a chain hoist and measured with a dynamometer, reacting against construction equipment.
(56) Subsurface conditions at the test site were evaluated by observation of one test pit. The soil profile appeared to be brown sandy clay. No evidence of groundwater was observed.
(57) Software Analysis of Design and Strength
(58) Prior to load testing, the design properties and strength of the acute Z-shaped pier were evaluated using the software Cold-Formed Steel Design Software (CFS), which is commercially available from RSG Systems. The software evaluates the strength of cold-rolled steel sections, based on the American Iron and Steel Institute (“AISI”) “Specification for the Design of Cold-Formed Steel Structural Members” Code.
(59) The full section properties of the pier as determined by the CFS software are set forth in Table 2.
(60) TABLE-US-00002 TABLE 2 Full Section Properties Area 2.1353 in.sup.2 Wt. 0.0072599 k/ft Width 16.947 in Ix 20.461 in.sup.4 rx 3.0956 in Ixy −0.004 in.sup.4 Sx(t) 5.1159 in.sup.3 y(t) 3.9995 in α 0.014 deg Sx(b) 5.1159 in.sup.3 y(b) 3.9995 in Height 7.9991 in Iy 2.286 in.sup.4 ry 1.0347 in xo 0.000 in Sy(1) 0.9747 in.sup.3 x(1) 2.3457 in yo 0.000 in Sy(r) 0.9747 in.sup.3 x(r) 2.3457 in jx 0.000 in Width 4.6913 in jy 0.000 in I1 20.461 in.sup.4 r1 3.0956 in I2 2.286 in.sup.4 r2 1.0347 in Ic 22.747 in.sup.4 rc 3.2639 in Cw 54.770 in.sup.6 Io 22.747 in.sup.4 ro 3.2639 in J 0.011300 in.sup.4
(61) In addition, the buckling characteristics of the acute Z-shaped pier as determined by the CFS software are set forth in
(62) Based on these values and considering the application of lateral load at 60-inches above grade, it was anticipated that yield of the pile could occur at horizontal loads of approximately 4,260 pounds.
(63) Lateral Pier Load Testing
(64) The results of the lateral pile load testing are presented in
(65) Table 3 below sets forth the results of the lateral load test of Pier 1, which was a standard wide flange pier driven to a depth of 6 feet. Further,
(66) TABLE-US-00003 TABLE 3 Lateral Load Test - Pier 1 Pile Number: 1 Tested by: PR Ground surface Condition: Grass Pile Size: Wide Flange Beam Height of top of pile from ground surface 62 in Height of pull chain above ground surface 62 in Height of top measurement 60.75 in Height of bottom measurement 6 in Pile Driven Depth 6 ft STABILIZED READING LOAD Top of Pile Top of Pile Bottom of Bottom of Pile (lbs) Reading Defection Pile Reading Defection 0 1.984 0.000 1.532 0.000 230 2.156 0.172 1.557 0.025 430 2.280 0.296 1.606 0.074 590 2.375 0.391 1.621 0.089 800 2.507 0.523 1.660 0.128 1000 2.625 0.641 1.680 0.148 1210 2.750 0.766 1.720 0.188 1410 2.873 0.889 1.745 0.213 1610 3.008 1.024 1.766 0.234 1800 3.116 1.132 1.799 0.267 2000 3.252 1.268 1.830 0.298 2200 3.358 1.374 1.861 0.329 2400 3.504 1.520 1.894 0.362 2600 3.631 1.647 1.931 0.399 2800 3.768 1.784 1.956 0.424 3000 3.911 1.927 1.988 0.456 3200 4.059 2.075 2.032 0.500 3400 4.207 2.223 2.075 0.543 ~3600 Failure
(67) Table 4 below sets forth the results of the lateral load test of Pier 2, which was an acute Z-shaped pier driven to a depth of 6 feet. Further,
(68) TABLE-US-00004 TABLE 4 Lateral Load Test - Pier 2 Pile Number: 2 Tested by: PR Ground surface Condition: PV Pile Lateral Pile Size: Stabilized Z Load 1 Height of top of pile from ground surface 61.75 in Height of pull chain above ground surface 61.75 in Height of top measurement 60.75 in Height of bottom measurement 6 in Pile Driven Depth 6 ft STABILIZED READING LOAD Top of Pile Top of Pile Bottom of Pile Bottom of Pile (lbs) Reading Defection Reading Defection 0 1.999 0.000 0.883 0.000 280 2.109 0.110 0.921 0.038 460 2.198 0.199 0.946 0.063 600 2.286 0.287 0.970 0.087 800 2.387 0.388 0.990 0.107 990 2.472 0.473 1.015 0.132 1200 2.581 0.582 1.041 0.158 1420 2.712 0.713 1.072 0.189 1600 2.812 0.813 1.095 0.212 1590 2.848 0.849 1.120 0.237 1790 2.932 0.933 1.131 0.248 2000 3.075 1.076 1.166 0.283 2240 3.216 1.217 1.200 0.317 2400 3.331 1.332 1.235 0.352 2540 3.445 1.446 1.272 0.389 2720 3.598 1.599 1.361 0.478 2950 3.769 1.770 1.358 0.475 3150 3.988 1.989 1.431 0.548 3360 4.235 2.236 1.501 0.618 3500 4.545 2.546 1.585 0.702 ~3600 Failure, Pile Buckled
(69) Table 5 below sets forth the results of the lateral load test of Pier 3, which was a standard wide flange pier driven to a depth of 6 feet. Further,
(70) TABLE-US-00005 TABLE 5 Lateral Load Test - Pier 3 Pile Number: 3 Tested by: PR Ground surface Condition: Grass Pile Size: Wide Flange Beam Height of top of pile from ground surface 61 in Height of pull chain above ground surface 61 in Height of top measurement 60.75 in Height of bottom measurement 6 in Pile Driven Depth 6 ft STABILIZED READING LOAD Top of Pile Top of Pile Bottom of Pile Bottom of Pile (lbs) Reading Defection Reading Defection 0 2.432 0.000 0.969 0.000 750 2.893 0.461 1.092 0.123 1520 3.374 0.942 1.198 0.229 1840 3.594 1.162 1.248 0.279 2230 3.839 1.407 1.313 0.344 0 2.517 0.085 1.010 0.041 1510 3.449 1.017 1.229 0.260 2240 3.878 1.446 1.330 0.361 2600 4.115 1.683 1.393 0.424 3360 4.711 2.279 1.539 0.570 2990 4.562 2.130 1.524 0.555 3700 5.111 2.679 1.658 0.689 4125 Failure
(71) Table 6 below sets forth the results of the lateral load test of Pier 4, which was an acute Z-shaped pier driven to a depth of 6 feet. Further,
(72) TABLE-US-00006 TABLE 6 Lateral Load Test - Pier 4 Pile Number: 4 Tested by: PR Ground surface Condition: Grass Pile Size: Stabilized Z Height of top of pile from ground surface 62 in Height of pull chain above ground surface 62 in Height of top measurement 60.75 in Height of bottom measurement 6 in Pile Driven Depth 6 ft STABILIZED READING LOAD Top of Pile Top of Pile Bottom of Bottom of Pile (lbs) Reading Defection Pile Reading Defection 0 2.479 0.000 1.032 0.000 750 2.894 0.415 1.141 0.109 1480 3.282 0.803 1.250 0.218 1860 3.517 1.038 1.297 0.265 2290 3.771 1.292 1.374 0.342 0 2.630 0.151 1.081 0.049 1550 3.441 0.962 1.298 0.266 2230 3.779 1.300 1.384 0.352 2620 4.003 1.524 1.443 0.411 3320 4.586 2.107 1.623 0.591 3000 4.476 1.997 1.602 0.570 3720 4.989 2.510 1.736 0.704 4125 Failure
(73) Table 7 below sets forth the results of the lateral load test of Pier 5, which was a standard wide flange pier driven to a depth of 5.5 feet. Further,
(74) TABLE-US-00007 TABLE 7 Lateral Load Test - Pier 5 Pile Number: 5 Tested by: PR Ground surface Condition: Grass Pile Size: Wide Flange Bean Height of top of pile from ground surface 61.5 in Height of pull chain above ground surface 61.5 in Height of top measurement 60.75 in Height of bottom measurement 6 in Pile Driven Depth 6 ft STABILIZED READING LOAD Top of Pile Top of Pile Bottom of Pile Bottom of Pile (lbs) Reading Defection Reading Defection 0 1.614 0.000 2.718 0.000 790 2.159 0.545 2.827 0.109 1520 2.591 0.977 2.930 0.212 1870 2.804 1.190 2.977 0.259 2260 3.041 1.427 3.037 0.319 0 1.730 0.116 2.755 0.037 1890 2.681 1.067 2.990 0.272 2260 3.072 1.458 3.056 0.338 2640 3.288 1.674 3.102 0.384 3350 3.771 2.157 3.225 0.507 2990 3.648 2.034 3.219 0.501 3700 4.073 2.459 3.304 0.586 4100 4.388 2.774 3.389 0.671 0 1.870 0.256 2.806 0.088
(75) Table 8 below sets forth the results of the lateral load test of Pier 6, which was an acute Z-shaped pier driven to a depth of 5.5 feet. Further,
(76) TABLE-US-00008 TABLE 8 Lateral Load Test - Pier 6 Pile Number: 6 Tested by: PR Ground surface Condition: Grass Pile Size: Stabilized Z Height of top of pile from ground surface 62 in Height of pull chain above ground surface 62 in Height of top measurement 60.75 in Height of bottom measurement 6 in Pile Driven Depth 6 ft STABILIZED READING LOAD Top of Pile Top of Pile Bottom of Pile Bottom of Pile (lbs) Reading Defection Reading Defection 0 1.776 0.000 1.053 0.000 750 2.127 0.351 1.138 0.085 1520 2.505 0.729 1.238 0.185 1890 2.699 0.923 1.284 0.231 2250 2.897 1.121 1.335 0.282 0 1.929 0.153 1.123 0.070 1520 2.621 0.845 1.282 0.229 2270 2.963 1.187 1.364 0.311 2630 3.167 1.391 1.424 0.371 3250 3.624 1.848 1.557 0.504 2990 3.552 1.776 1.545 0.492 3700 4.029 2.253 1.688 0.635 4090 4.520 2.744 1.847 0.794 0 2.482 0.706 1.345 0.292
(77) Table 9 below sets forth the results of the lateral load test of Pier 7, which was a standard wide flange pier driven to a depth of 5.5 feet. Further,
(78) TABLE-US-00009 TABLE 9 Lateral Load Test - Pier 7 Pile Number: 7 Tested by: PR Ground surface Condition: Grass Pile Size: Wide Flange Beam Height of top of pile from ground surface 61.25 in Height of pull chain above ground surface 61.25 in Height of top measurement 60.75 in Height of bottom measurement 6 in Pile Driven Depth 5.5 ft STABILIZED READING LOAD Top of Pile Top of Pile Bottom of Pile Bottom of Pile (lbs) Reading Defection Reading Defection 0 1.626 0.000 1.427 0.000 750 2.114 0.488 1.533 0.106 1500 2.549 0.923 1.625 0.198 1880 2.775 1.149 1.681 0.254 2250 2.991 1.365 1.723 0.296 0 1.789 0.163 1.470 0.043 1500 2.627 1.001 1.653 0.226 2270 3.042 1.416 1.743 0.316 2620 3.246 1.620 1.788 0.361 3360 3.750 2.124 1.907 0.480 3010 3.612 1.986 1.891 0.464 3730 4.007 2.381 1.985 0.558 4120 4.350 2.724 2.066 0.639 0 1.986 0.360 1.540 0.113
(79) Table 10 below sets forth the results of the lateral load test of Pier 8, which was an acute Z-shaped pier driven to a depth of 5.5 feet. Further,
(80) TABLE-US-00010 TABLE 10 Lateral Load Test - Pier 8 Pile Number: 8 Tested by: PR Ground surface Condition: Grass Pile Size: Stabilized Z Height of top of pile from ground surface 62.75 Height of pull chain above ground surface 62.75 Height of top measurement 60.75 in Height of bottom measurement 6 in Pile Driven Depth 5.5 ft STABILIZED READING LOAD Top of Pile Top of Pile Bottom of Pile Bottom of Pile (lbs) Reading Defection Reading Defection 0 1.244 0.000 1.605 0.000 750 1.636 0.392 1.705 0.100 1500 1.974 0.730 1.785 0.180 1880 2.178 0.934 1.833 0.228 2260 2.396 1.152 1.901 0.296 0 1.388 0.144 1.668 0.063 1510 2.091 0.847 1.840 0.235 2270 2.440 1.196 1.914 0.309 2620 2.629 1.385 1.972 0.367 3360 3.217 1.973 2.139 0.534 2990 3.105 1.861 2.131 0.526 3700 3.582 2.338 2.263 0.658 4090 4.068 2.824 2.420 0.815 0 2.000 0.756 1.919 0.314
(81) Table 11 below sets forth the results of the lateral load test of Pier 9, which was a standard wide flange pier driven to a depth of 5 feet. Further,
(82) TABLE-US-00011 TABLE 11 Lateral Load Test - Pier 9 Pile Number: 9 Tested by: PR Ground surface Condition: Grass Pile Size: Wide Flange Beam Height of top of pile from ground surface 61.5 in Height of pull chain above ground surface 61.5 in Height of top measurement 60.75 in Height of bottom measurement 6 in Pile Driven Depth 5 ft STABILIZED READING LOAD Top of Pile Top of Pile Bottom of Bottom of Pile (lbs) Reading Defection Pile Reading Defection 0 2.404 0.000 1.319 0.000 740 2.840 0.436 1.411 0.092 1510 3.260 0.856 1.512 0.193 1870 3.488 1.084 1.573 0.254 2240 3.741 1.337 1.642 0.323 0 2.587 0.183 1.391 0.072 1530 3.410 1.006 1.574 0.255 2260 3.811 1.407 1.671 0.352 2620 4.107 1.703 1.750 0.431 3375 Failure
(83) Table 12 below sets forth the results of the lateral load test of Pier 10, which was an acute Z-shaped pier driven to a depth of 5 feet. Further,
(84) TABLE-US-00012 TABLE 12 Lateral Load Test - Pier 10 Pile Number: 10 Tested by: PR Ground surface Condition: Grass Pile Size: Stabilized Z Height of top of pile from ground surface 62.25 in Height of pull chain above ground surface 62.25 in Height of top measurement 60.75 in Height of bottom measurement 6 in Pile Driven Depth 5 ft STABILIZED READING LOAD Top of Pile Top of Pile Bottom of Bottom of Pile (lbs) Reading Defection Pile Reading Defection 0 1.523 0.000 0.557 0.000 770 1.881 0.358 0.648 0.091 1490 2.316 0.793 0.763 0.206 1860 2.614 1.091 0.851 0.294 2230 2.994 1.471 0.973 0.416 0 1.927 0.404 0.719 0.162 1550 2.695 1.172 0.901 0.344 2260 3.162 1.639 1.031 0.474 2600 3.616 2.093 1.176 0.619 Failure
(85) Table 13 below sets forth the results of the lateral load test of Pier 11, which was a standard wide flange pier driven to a depth of 5 feet. Further,
(86) TABLE-US-00013 TABLE 13 Lateral Load Test - Pier 11 Pile Number: 11 Tested by: PR Ground surface Condition: Grass Pile Size: Wide Flange Beam Height of top of pile from ground surface 60″ Height of pull chain above ground surface 60″ Height of top measurement 59.5″ Height of bottom measurement 6 in Pile Driven Depth 5 ft STABILIZED READING LOAD Top of Pile Top of Pile Bottom of Pile Bottom of Pile (lbs) Reading Defection Reading Defection 0 2.350 0.000 1.158 0.000 750 2.813 0.463 1.258 0.100 1480 3.268 0.918 1.358 0.200 1870 3.522 1.172 1.421 0.263 2230 3.816 1.466 1.505 0.347 0 2.547 0.197 1.232 0.074 1510 3.434 1.084 1.424 0.266 2230 3.874 1.524 1.530 0.372 2600 4.181 1.831 1.606 0.448 2970 4.591 2.241 1.743 0.585 3270 5.075 2.725 1.898 0.740 3750 Failure
(87) Table 14 below sets forth the results of the lateral load test of Pier 12, which was an acute Z-shaped pier driven to a depth of 5 feet. Further,
(88) TABLE-US-00014 TABLE 14 Lateral Load Test - Pier 12 Pile Number: 12 Tested by: PR Ground surface Condition: Grass Pile Size: Stabilized Z Height of top of pile from ground surface 62.25 Height of pull chain above ground surface 62.25 Height of top measurement 60.75 in Height of bottom measurement 6 in Pile Driven Depth 5 ft STABILIZED READING LOAD Top of Pile Top of Pile Bottom of Bottom of Pile (lbs) Reading Defection Pile Reading Defection 0 1.736 0.000 1.768 0.000 750 2.317 0.581 1.958 0.190 1470 2.978 1.242 2.180 0.412 1850 3.383 1.647 2.326 0.558 2240 3.888 2.152 2.486 0.718 0 2.695 0.959 2.172 0.404 1510 3.545 1.809 2.415 0.647 2240 4.066 2.330 2.565 0.797 2570 4.563 2.827 2.738 0.970 3375 Failure
(89) Based on the load testing, the acute Z-shaped pier (called “Stabilized Z” in the tables and figures relating to the testing) has a similar or better deflection response when compared to the standard wide flange pier under lateral loading at the embedment depths of 5.5 and 6 feet. As a result, the acute Z-shaped pier may provide cost savings as a result of being lighter and slightly shorter in comparison to the standard wide flange pier while maintaining the same or better deflection response. For the piers tested at 5 feet of embedment, all four piers (both the acute Z-shaped and standard wide flange piers) exhibited excessive deflections at lower loads. It is expected that for most tracker designs, however, foundation embodiments will be greater than 5 feet, because, for typical tracker loads, there are very few sites where the soils are strong enough to resist the loads while also being soft enough to be drivable.
(90) Although the disclosure has been described with reference to preferred embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the disclosed apparatus, systems and methods.