Patent Abstract:
A novel apparatus and method are disclosed for testing piles for load bearing capacity. The novel means and method of the present invention include applying a static compressive force on a pile or group of piles to be tested for load bearing capacity, receiving an equal and opposite reaction force on an I-beam, providing at least two reaction anchor assemblies on opposite sides of the pile, and bracing the I-beam by the two reaction anchor assemblies to hold the I-beam stationary in counter-action against the opposite reaction force on the I-beam. In one aspect, each reaction anchor assembly has an anchoring head, a pipe column, a center, a pulling rod passing through the center, a pair of the swingable anchoring plates, and a frusto-cone for pivoting the swingable anchoring plates. In one aspect, the pipe column has four fins welded longitudinally along the pipe column. In one aspect, the reaction anchor assembly is preassembled for transportation to a pile test site. The novel means and method retrieve the reaction anchor assemblies from the ground after completion of the pile test and reuse them from one pile test site to another.

Full Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     This invention relates to an apparatus and method for testing load bearing capacity on a pile or group of piles. In one aspect, this invention relates to novel apparatus and method for testing load bearing capacity on a pile or group of piles, utilizing a reaction anchor apparatus and method. 
     2. Background 
     In the construction industry, various types and shapes of piles are utilized for constructing foundations on the piles. These foundations are the structural supports upon which many types of constructions are built. Foundations support the loads imposed upon them and, hence, the loads imposed upon the piles, by such constructions as high rise buildings, power plants, river dams, and many other constructions. 
     Among the most common types and shapes of piles are timber piles, steel pipe piles, H-Piles, L-Piles, precast concrete piles, and cast-in-place concrete piles. These piles are in-stalled vertically or battered at an angle. 
     Piles are forced deep down into the soil by repetitive blows on their tops. These powerful blows are provided by pile-driving machines, also known as hydraulic hammers. Piles also can be poured-in, i.e., cast-in-place, by drilling a deep hole in the soil, then filling it with concrete. Generally, reinforcement steel rods, also known as rebar, are introduced into the hole prior to filling it with concrete. 
     The most commonly used method of installation of piles is by beating them down into the ground by means of a pile-driving machine. 
     Through the years, the construction industry has developed apparatus and testing methods for determining the capability of a vertical pile, a batter pile, or a group of piles to resist a required level of static compression loads as actually applied on the pile or group of piles. These testing methods determine whether a pile or group of piles has adequate bearing capacity or not. 
     Testing methods have been standardized by the American Society for testing materials, also known as ASTM. The Standard Test Method For Piles Under Static Axial Compressive Load, designation D1143-81, (reapproved 1987) covers pile testing utilizing conventional apparatus and methods for determining the capability of piles to resist a static compression load as actually applied on the piles. 
     INTRODUCTION TO THE INVENTION 
     According to ASTM D1143-81, single piles must be tested to 200% of the anticipated design load, while pile groups must be tested to 150% of the group design load. 
     Conventionally, for testing an individual pile, two additional piles have to be installed, using the same method and equipment utilized for installing the pile under test. These additional piles are driven into the soil on two diametrically opposing sides of the pile to be tested and at not less than seven feet from the pile being tested. These additional piles are known in the trade as anchor piles. 
     A test beam then is installed across the tops of the anchor piles, tying them to the beam and above the pile under test, forming what is known in the trade as a reaction frame. This test beam is set on a hydraulic jack, which in turn is set on top of the pile under test. 
     Upward hydraulic push is applied by the jack against the beam. The beam cannot move up because it is tied onto the anchor piles. As a result, the hydraulic power, i.e., the force exerted by the hydraulic jack, is applied downwardly against the top of the pile under test. These forces are applied incrementally, increasing at pre-established time intervals and held then at the maximum predetermined test loading for a specified length of time. 
     Certain instrumentation is utilized for determining the axial loading and for determining any movements, e.g., axial, rotational, and lateral, of the pile under test. 
     If the test proves the capability of the pile to resist the specified axially applied compressive loading, and if there are no other deviations beyond acceptable standards, then that pile is determined to be fit to be used for its intended purposes, i.e., it has adequate bearing capacity. 
     Testing a group of piles instead of a single pile utilizes the same procedure, but in the case of a group of piles, the various piles in the group are capped by a common cap, and the test load is applied uniformly upon the pile cap. Pile caps generally are poured, reinforced concrete slabs, specifically engineered for that purpose. A larger number of anchor pile pairs is required when testing pile groups. 
     After the test, anchor piles are left in place, after sawing off their tops, i.e., after sawing-off the top portion of the pile protruding above ground. It is extremely difficult and expensive to pull those anchor piles out of the ground. 
     Utilizing anchor piles for testing an installed pile or a group of piles presents several drawbacks. 
     One drawback of the conventional pile testing apparatus and methods is the large installation cost of driving into the soil one, two, or more pairs of anchor piles per each single pile or group of piles to be tested. 
     Another drawback of the conventional pile testings is the difficulty in handling the long and heavy anchor piles required for the testings, e.g., requiring a tractor and a trailer for their transportation, requiring a special crane for lifting in or out of the trailer, requiring an expensive, cumbersome pile driving machine for driving the anchor piles into the ground. 
     Another drawback of the conventional pile testings is the difficulty of setting the long and heavy anchor piles in a vertical position for driving them into the ground. 
     Yet another drawback of the conventional pile testings is the loss of the anchor piles, because after the test is completed, they are not reusable in future tests, and therefore, their top ends protruding above the ground have to be sawed off, abandoning the pile in the ground. 
     It is an object of the present invention to provide anchoring apparatus and installation methods which substantially reduce the cost of testing piles or group of piles. 
     Another object of the present invention is to provide anchoring apparatus and methods which simplify the pile testing process. 
     Yet another object of the present invention is to provide anchoring apparatus and methods for the testing of piles which simplify transportation and eliminate utilizing a tractor and a trailer. 
     Still another object of the present invention is to provide anchoring apparatus and methods for the testing of piles which do not require the use of a pile driving machine. 
     Another object of the present invention is to provide anchoring apparatus and methods for the testing of piles which do not require the use of anchor piles for the pile testing process. 
     Yet another object of the present invention is to provide anchoring apparatus and methods for the testing of piles which are reusable. 
     These and other objects of the present invention will become apparent from a careful review of the detailed description and the figures of the drawings, which follow. 
     SUMMARY OF THE INVENTION 
     The apparatus and method of the present invention provide novel means and method for testing piles for load bearing capacity. The novel means and method of the present invention include applying a static compressive force on a pile or group of piles to be tested for load bearing capacity, receiving an equal and opposite reaction force on an I-beam, providing at least two reaction anchor assemblies on opposite sides of the pile, and bracing the I-beam by the two reaction anchor assemblies to hold the I-beam stationary in counter-action against the opposite reaction force on the I-beam. In one aspect, each reaction anchor assembly has an anchoring head, a pipe column, a center, a pulling rod passing through the center, a pair of swingable anchoring plates and preferably two pairs of swingable anchoring plates, and a frusto-cone for pivoting the swingable anchoring plates. In one aspect, the pipe column has four fins welded longitudinally along the pipe column. In one aspect, the reaction anchor assembly is preassembled for transportation to a pile test site. The novel means and method for testing piles provide for retrieving the reaction anchor assemblies from the ground after completion of the pile test and reusing the reaction anchor assemblies from one pile test site to another. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an elevation view showing the single pile testing apparatus of the existing art. 
     FIG. 2 is an elevation view showing the pile group testing apparatus of the existing art. 
     FIG. 3 is an elevation view, partially in section, showing a single pile testing apparatus of the present invention. FIG. 3 also shows some measuring instruments. 
     FIG. 4 is a perspective view of FIG. 3 without showing instrumentation. 
     FIG. 5 is an elevation view, partially in section, of a reaction anchor and support assembly in accordance with the apparatus and methods of the present invention. FIG. 5 shows a hydraulic assembly utilized for anchoring the reaction anchor and support assembly, also in accordance with the apparatus and methods of the present invention. 
     FIG. 6 is a detail view of a hydraulic system component part of the present invention, shown in elevation. 
     FIG. 7 is a detail elevation view of a hydraulic system component part of the present invention, also showing a load cell and a read-out with a graph print out. 
     FIG. 8 is a detail perspective view of a rod-centering box component part of the present invention shown in elevation on FIG.  3 . FIG. 8 shows a centering and support plate lifted up from the box. 
     FIG. 9 is an elevation view, partially in section, showing a pile group testing apparatus of the present invention, utilizing a concrete pile cap. FIG. 9 also shows some measuring instruments. 
    
    
     DETAILED DESCRIPTION 
     FIG.  1  and FIG. 2 depict apparatus and method representing the conventional testing apparatus and method for testing vertical piles, as shown on ASTM D1143-81 (reapproved 1987). FIG. 1 depicts the conventional testing apparatus and method for testing a single pile. FIG. 2 depicts the conventional testing apparatus and method for testing a group of piles. 
     Referring now to FIG. 1, a single pile  1  is shown as having been driven into soil  17 . A pair of anchor piles  7  also have been driven into soil  17 , at a distance at least seven feet away from or clear of pile  1 , i.e., away from the pile  1  under test. A bottom flange  19  of a test beam  6  is set on top of a bearing plate  5  of a piston ram  4  of a hydraulic cylinder  2 . The hydraulic cylinder  2  is set on a test plate  3 , which is centered on top of the individual pile  1 , i.e., the single pile  1 . 
     The test beam  6  is tied to the anchor piles  7  by means of a series of connecting rods  8 , a pair of plates  9  on a top flange  18  of the beam  6 , and the connecting rods  8  are secured by a series of threaded nuts  10 , threaded down against the plates  9 . 
     By the conventional method, a powerful, upwardly driven push is provided by the piston ram  4  of the hydraulic cylinder  2 , as represented by an arrow  15 . This upwardly driven push is exerted upon the test beam  6 , by means of a bearing plate  5 , which bears on the bottom flange  19  of the beam  6 . The beam  6  is fixedly connected to the anchor piles  7  by means of the threaded nuts  10 , tightened on the connecting rods  8 , against the plates  9 . As a result, the beam  6  cannot move up. The forceful push of the pistons  4  is effectively resisted by the anchor piles  7  because of the friction between the anchor piles  7  and the soil  17 . An equivalent forceful push therefore is exerted downwardly on the test plate  3  and, as a result, on the individual pile  1 . 
     Accordingly to ASTM D1143-81 (reapproved 1987), the load applied upon the pile  1 , which is the pile under test, must be 200% of the anticipated individual pile  1  design load. 
     The scope of purpose for testing piles is to determine if the pile has adequate bearing capacity, by measuring the response of the pile, e.g., the pile  1 , to a static, compressive load, axially applied, as shown by an arrow  16  of FIG.  1 . 
     In addition, pile testings also are utilized for measuring pile movements under axial loading. FIG. 1 shows a pair of dial gages  11 , connected by means of a pair of stems  20  to the pile  1 , at a pair of lugs  14  and to a pair of reference beams  13  by means of a pair of supports  12 . 
     Referring now to FIG. 2, the conventional testing apparatus and method for a group of piles  40  is represented. Pile group  40  includes, by the way of an example, the two piles  40  which have been driven into a soil  53 . A series of anchor piles  47  also have been driven into the soil  53  at a distance at least seven feet away from or clear of any pile  40 , i.e., the pile  40  of the pile group under test. A bottom flange  57  of a test beam  56  is set on top of a bearing plate  45  of a ram  44  of a hydraulic cylinder  43 . The hydraulic cylinder  43  is set on a test plate  42 , which in turn is set on a pile cap  41 . The pile cap  41  is centered on top of pile group  40 . The pile cap  41  is constructed of reinforced concrete, which is engineered to bear the anticipated load. 
     The test beam  56  has a pair of beams  61  on its top flange  46 . A pair of beams  58  are set with their bottom flanges  59  on top of the I-beams  61 . This I-beam set up is all tied down to the anchor piles  47  by means of a series of connecting rods  48  and threaded nuts  52 , with a plate  51  on top of each flange  60 . The threaded nuts  52  are tightened down against the plates  51 . 
     By the conventional method, a powerful, upwardly driven push is provided by the piston  44  of the hydraulic cylinder  43 , as represented by an arrow  54 . This upwardly driven push is exerted upon the test beam  56  by means of the bearing plate  45 , which bears on the bottom flange  57  of the beam  56 . The beam  56  is fixedly connected to the anchor piles  47  by means of the threaded nuts  52  tightened on the connecting rods  48 , against the plates  51 . As a result, the beam  56  cannot move up. The forceful push of the piston  44  is effectively resisted by the anchor piles  47  because of the friction between the piles  47  and the soil  53 . An equivalent, forceful push is exerted therefore downwardly upon the test plate  42 , the pile cap  41 , and the pile group  40 , as represented by an arrow  55 . 
     Accordingly to ASTM D1143-81 (reapproved 1987), the load applied upon the pile group  40 , which is the pile group under test, must be 150% of the anticipated pile group  40  design load. 
     These ASTM tests are performed to determine if the pile group has adequate bearing capacity by measuring the response of the pile group, e.g., the pile group  40 , to a static, compressive load applied axially, as shown in FIG.  2 . 
     The pile group  40  also is tested to determine movements which occur under loading. FIG. 2 shows a pair of dial gages  51  connected by means of a pair of stems  49  to a pile cap  41  and to a pair of reference beams  53  by means of a pair of supports  52 . 
     Referring now to FIG. 3, a pair of reaction anchor and support assemblies  125  in accordance with the apparatus and the methods of the present invention are shown in the process of testing a single pile  90  under a static, axial load, provided by a hydraulic assembly  145 . The reaction anchor and support assemblies  125  provide a point of resistance for a pair of hydraulic cylinders  93  to push against, as the hydraulic cylinders  93  exert a specified testing load on the pile  90 , as further described in this detailed description. The reaction anchors and support assemblies  125  are manufactured by SAFE Foundations, Inc., of Pittsburgh, Pa. 
     The hydraulic cylinders  93  are set on a bearing plate  91 , also known as a test plate  91 , with a pair of pistons  94 , respectively, upon which a bearing plate  92  is set. The hydraulic assembly could include only a one cylinder and one piston set instead of the pair of cylinders and pistons as shown in FIGS. 3 and 6. A load cell  121  is set between the bearing plate  92  and a bearing plate  122 . The bearing plates  91 ,  92 , and  122  are of sufficient thickness to support the test loads provided by the hydraulic assembly  145  without bending, but not less than two inches thick. 
     The plate  122  bears against a flange  142  of a novel I-beam assembly  116 . The I-beam assembly  116  bears against an I-beam assembly  115 , which is identical to the beam assembly  116 . A pair of flanges  143  of the I-beam assembly  115  are set on top of a pair of flanges  105  of the I-beam assembly  116 . The beam assembly  115  is set at ninety degrees of the beam assembly  116  and on top of the beam assembly  116 , as shown in FIG. 4, a perspective view, showing some of the elements shown in FIG.  3 . 
     Referring now to FIGS. 3,  4 , and  8 , each of the beam assemblies  115  and  116  is constructed of two parallel I-beams, with one rod centering box  96  at each end of each assembly  115  and  116 . A detail of the rod centering box  96  is shown in FIG. 8, a perspective view of rod centering box  96 . 
     One box  96  is welded at each end of each beam assembly  115  and  116 . The boxes  96  are made of plates  99  welded to the top flanges  105  and  106  of the beam assembly  116  and  115 , respectively, and of L-shaped bars  100 , also welded to the flanges  105  and  106 , respectively. The rod centering boxes  96  are completed by plates  97 , also welded to flanges  105  and  106  respectively. The plates  99  are also welded to the angled bars  100  and to the plates  97 . Angled bars  104  are welded to each end of the I-beams  115  and  116 , respectively. With one rod centering box  96 , and one angled bar  104  welded to each end of each pair of I-beams, very strong, novel reaction frames, i.e., beam assemblies  115  and  116 , are formed. Support plates  101 , shown lifted-up from box  96  in FIG. 8 are utilized to receive threaded rods  102  of the reaction anchor and support assemblies  125 . Nuts  103  in FIGS. 3 and 4 are threaded onto the rods  102  and tightened against the support plates  101 . The plates  101  can slide inside their respective centering box  96  to facilitate positioning the beam assemblies  115  and  116  over rods  102 . 
     Referring now to FIGS. 3 and 7, the hydraulic assembly  145  is shown set upon the test plate  91 . The test plate  91  is set on top of the pile  90 , which is the pile under test, as shown in FIG.  3 . 
     To test the pile  90  for determining its capability of supporting its design load, a compressive load is axially applied upon the longitudinal axis of the pile  90 , the compressive load being provided by the hydraulic assembly  145 . 
     The pistons  94  of the hydraulic assembly  145  forcefully push, upwardly, against the bearing plate  92 . This upward push of the pistons  94  is transmitted to the beam assemblies  115  and  116 . Since the beam assemblies  115  and  116  are anchored by the reaction anchor and support assemblies  125 , the beam assemblies  115  and  116  cannot move upwardly. The forceful upward push of the pistons  94 , as they are forced out of their respective cylinders  93 , is actually exerted axially, downwardly upon the pile  90 , by means of the bottoms of the cylinders  93 , upon the bearing plate  91 . 
     Referring to FIG. 3, a pair of dial gages  109  have their stems  118  connected to a top surface  191  of the bearing plate  91  and to a pair of reference beams  110  by means of a pair of supports  147 . The stems  118  must have, at a minimum, two inches (5 cm) of travel, must have a precision of at least 0.01 inches (0.25 millimeters) and must read to one sixty-fourth (1/64) of an inch (4 mm). 
     The dial gages  109  provide the measurement of any longitudinal axial movement of the pile  90  under the axial loading provided by the hydraulic assembly  145 . Any axial movement beyond that specified renders the pile  90  unacceptable for its specified load. 
     Referring to FIGS. 3 and 6, the hydraulic assembly utilized in the apparatus and the method of the present invention could include a single hydraulic cylinder with its piston or a pair of cylinders  93  of a hydraulic assembly  95  of FIG. 6, with a pair of pressure gages  117 , one pressure gage  117  for each hydraulic cylinder  93  and a master pressure gage  116 , and further includes a hydraulic pump  113  and an automatic pressure control device  114 . The cylinders  93  are connected to the pump  113  by a pair of common manifolds  111  and hoses  112 . The complete hydraulic assembly  95  is to be calibrated as a unit, including the hydraulic cylinders  93 , the pistons  94 , the pressure gages  117  and  116 , the pump  113 , and the automatic pressure control device  114 . 
     FIG. 7 represents the preferred embodiment of the hydraulic means utilized by the apparatus and the methods of the present invention. The hydraulic assembly  145  is very similar to the hydraulic assembly  95 . Nevertheless, the hydraulic assembly  145  utilizes a calibrated load cell  121  between the bearing plate  92  and the bearing plate  122 . In accord with the apparatus and the methods of the present invention, the calibrated load cell  121  is connected to a read-out and load graph recorder  124 . The read-out recorder  124  provides a graph  148  showing the load applied during a 24-hour period. The calibrated load cell  121  and the read-out and load graph recorder  124  substantially improve the accuracy and reliability of the measurements of the loads applied to the pile-under-test  90 . The preferred embodiment for the hydraulic means, e.g., the hydraulic assembly  145 , also includes the pressure gages  117 , one for each hydraulic cylinder  93  and the master pressure gage  116 , the hydraulic pump  113 , and the automatic pressure control  114 . The cylinders  93  are connected to the pump  113  by the common manifolds  111  and the hoses  112 . This apparatus and method provide a dual measuring system. The load cell  121  must be calibrated to an accuracy of not less than 2% of the applied load. 
     Referring again to FIG. 3, the reaction anchor and support assemblies  125 , also referred to as anchor assemblies  125 , are shown inside earthen holes  126 . The reaction anchor and support assemblies  125  include anchoring heads  133  and a pipe column  128 , which has four fins  129 , only three shown, welded longitudinally to the surface of pipe column  128  and at ninety degrees to each other. The pipe columns  128  also have top plates  130  welded to their tops, which have a center hole to allow Dywidag Rod  102  pass through it, with a minimum clearance, in order to allow Dywidag nuts  132  to be tightened against the plates  130  when threaded down on the Dywidag rods  102 . The Dywidag rods, the nuts, and other Dywidag products are manufactured by Dywidag-Systems International, U.S.A., Inc., of Fairfield, N.J. 
     The anchoring heads  133  have the Dywidag rods  125  and a plate support  138  formed by four ninety-degree bars, only two being shown, with a plate  137  welded on their top and four compaction and consolidation pivoting plates  139 , only three being shown. A collar  135  is welded on top of the plate  137  and is utilized to insert end  134  of the pipe column  128  into the collar  135  or over the collar  135 , depending on pipe sizes utilized. Four bolts  136 , only three shown, are utilized for firmly securing the pipe column  128  to the anchor head  133 . The Dywidag rod  102  is inserted through a centerhole in a frusto-cone  140 . A Dywidag nut  141  is threaded on the end of the rod  102  and prevents the frusto-cone  140  from falling down. 
     A nut  168  is hand tightened on the Dywidag rod  102 , on top of the frusto-cone  140 , as seen in FIG.  4 . The main purpose of the nut  141  is to carry the frusto-cone  140  upwardly whenever the rod  102  is pulled up, during the process of anchoring the reaction anchor and support assembly  125 , prior to installing the test beam assemblies  115  and  116 . 
     During the installation of the reaction anchor and support assemblies  125 , hydraulic force is utilized for pulling up on the rod  102 . The pulling on the rod  102  forces the nut  141  to push the frusto-cone  140  upwardly, which in turn pushes the compaction and consolidation pivoting plates  139  upwardly and outwardly. The pulling on the rod  102  makes the pivoting plates  139  swing upwardly and outwardly, thereby compacting and consolidating soil  127  at the bottom of the earthen hole  126 , effectively anchoring the assembly  125  against the soil  127  at the bottom of the earthen hole  126 , thus providing the reaction point needed for the pile test. A nut  132  is threaded downwardly and hand tightened against the plate  130  at the top of the pipe column  128  in order to prevent the rod  102  and the frusto-cone  140  from moving back down. 
     The top end of the reaction anchor and support assembly  125  is left a few inches above grade in order to facilitate its retrieval for further use. Holes  131  are utilized for hooking a lifting device. 
     The reaction anchor and support assemblies  125  are installed at a distance of at least seven feet, clear distance, from the pile  90 . 
     The pile  90  of FIG. 3 is shown as a round, cylindrical pile. Nevertheless, the pile  90  can be an H-pile, an L-pile, a square pile, or an orthogonal pile. The pile  90  can be a concrete pile, whether cast-in-place or pre-cast, a pipe pile, or a timber pile, by the way of an example. 
     The test set up shown in FIG. 3 requires four reaction anchor and support assemblies  125 , as shown in FIG. 4, in order to provide an anchored reaction capacity, which is greater than the axial load applied to the pile  90  by the hydraulic assembly  145 . The axial loading or test loading required for testing single piles is at least 200% of the pile design load capacity. Nevertheless, smaller piles require smaller test loads, and only one pair of reaction anchor and support assemblies  125  are required for smaller piles. 
     On occasion, three pairs of reaction anchor and support assemblies  125  are required. In such cases, an additional beam assembly is installed upon the beam assembly  115  and at forty-five degrees from it. The additional pair of reaction anchor and support assemblies are installed as shown for the beam assemblies  115  and  116  and in a substantially similar manner as shown for the reaction anchor and support assemblies  125  of FIGS. 3 and 4. 
     Referring now to FIG. 5, one reaction anchoring and support assembly is shown of the four reaction anchoring and support assemblies of FIGS. 3,  4 , and  9 . The one reaction anchoring and support assembly is shown in the process of being installed inside a pre-augured earthen hole  126 , in preparation for utilization in the testing of the single pile  90  of FIG. 3 or group pile  180  of FIG.  9 . 
     The reaction anchor and support assembly  125  of FIG. 5 provides the anchored reaction capacity required to resist the upward push of the hydraulic assemblies  145  of FIGS. 3,  4 , and  9 . The upward push of the hydraulic assemblies  145  provides the resultant downward axial loading required for testing the single pile  90  of FIG. 3 or the group pile  180  of FIG.  9 . 
     The reaction anchor and support assemblies  125  are brought to the test site in one piece, pre-assembled, with the anchoring head  133  pre-attached to the rod  102  and with the rod  102  inside the pipe column  128 . The compaction and consolidation pivoting plates  139  come to the test site vertically down and parallel to the rod  102 , with the frusto-cone  140  below the tip end of the compaction and consolidation pivoting plates  139 . The frusto-cone  140  is sandwiched between the nut  168 , on its topside, as shown in FIG.  4  and the nut  141  on its bottom side as shown in FIG.  5 . The pivoting plates  139  come with breakable tie-wire (not shown) around them, in order to keep them in a vertical position, which facilitates lowering down the anchor assembly  125  inside the pre-augured earthen hole  126 . The nut  132  comes to the test site hand tightened against the plate  130 . 
     The reaction anchor and support assembly  125  is lowered down inside the earthen hole  126 . About six inches of the top end of the reaction anchor and support assembly  125  is left above ground level  166 . A centering collar  163  is placed over the assembly  125  and pushed down inside the earthen hole  126 , until its plate  162  rests on surface  166  of the soil  126 . The collar  163  is about twelve to eighteen inches long. The centering collar  163  is utilized for centering the reaction anchor assembly  125  inside the earthen hole  126  and to make sure it is fixed in a true, vertical and leveled position. When the correct leveling is attained, four pins  165  (only two are shown) are hammered down into the soil  127 , through holes  164  of the plate  162 , in order to immobilize the centering collar in a vertical position. 
     Next, the hydraulic assembly  150  is placed over the rod  102 , i.e., with the rod  102  passing through openings  155  and  156  on plates  152  and  153 , respectively. This is done by means of a crane, which is available at the job site anyways for handling the piles. The hydraulic assembly  145  of FIG. 7 could be utilized instead of the hydraulic assembly  150  of FIG. 5, if plates  91 ,  92 ,  94 , and the load cell  121  had an opening through their center, for allowing the rod  102  pass through it. 
     The preferred embodiment provides for utilizing one single hydraulic assembly to perform both the installation of all the reaction anchor and support assemblies  125  prior to testing, as well as providing the specified loading for testing the single pile  90  of FIG. 3 or the pile group  180  of FIG.  9 . In such an embodiment, the load cell  121  also has a center hole. If the load cell  121  also is utilized for installing the anchor assembly  125 , then it could be installed between the plate  91  of FIG.  7  and the plate  130  of FIG.  5 . The utilization of the load cell  121  and the read-out/graph recorder  124  is not a requirement for the installation of the reaction anchoring and support assemblies  125 . Nevertheless, the utilization of the load cell  121  and the read-out/graph recorder  124  is an additional quality control feature as well as a record keeping feature and a component part of the present invention. 
     When the hydraulic assembly  150  is set on top of the plate  130 , a plate  167  is placed over the rod  102  and set on top of the plate  153  to reduce the actual size of opening  156  so that the Dywidag nut  103  can be threaded down on the rod  102  and hand tightened against the plates  167  and  153 . 
     The hydraulic assembly  150  has cylinders  151  connected by means of hoses  158  through the assembly&#39;s inlets  157  to a hydraulic pump  159 . A master pressure gage  168  is provided in series with both the cylinders  151  and the pump  159 . A pressure gage  169  provides a reading of the pressures applied by the pistons  154 , in pounds per-square inch, p.s.i. The total force exerted by the assembly is directly proportional to the diameter of pistons  154 . The diameter of the pistons  154  determines the area in square inches of the cross section of each piston  154 , which pistons  154  are substantially identical pistons. Therefore, the total combined area is determined in advance. 
     The operator is provided with a simple table showing how many tons-force are equivalent to various p.s.i. readings from the gage  169 . The operator does not calculate anything. The compaction and consolidation pivoting plates  139  are at the bottom of the earthen hole  126  in a vertical position parallel to the rod  102 . The next step is to swing upwardly the pivoting plates  139  to anchor the assembly firmly against the soil  127  at the bottom of the hole  126 . 
     The operator provides hydraulic pressure to the cylinder  151 , through the bottom inlets  157 , which forces the pistons  154  upwardly. The pistons  154  forcefully push against the plates  153 ,  167  and the nut  103 . That forceful upward push as represented by arrows  160  and as exerted on the nut  103 , which is threaded onto the rod  102 , lifts the rod  102  up, which in turn carries the nut  141  up with it. The nut  141  is threaded to the bottom end of the rod  102 . The nut  141  pushes up the frusto-cone  140 , which in turn forces the pivoting plates  139  to break their tie-wire (not shown). The pivoting plates  139  are forced to swing upwardly, compacting and consolidating the soil  127  at the bottom of the hole  126  by the expanding plates, i.e., by the expansion of the pivoting plates  139 , thereby powerfully anchoring assembly the  125  to the soil at the bottom of the hole  126 . As the rod  102  is being slowly, yet powerfully pushed upwardly, the operator hand-tightens down the nut  132  against the plate  130 , thereby preventing the pivoting plates  139  from collapsing back down, which is a very rear situation. 
     Now the hydraulic assembly  150  is removed, by first reversing the flow of hydraulic fluid, which now is pumped by the pump  159 , through the upper inlets  157 , which in turn brings the pistons  154  back inside of their respective cylinders  151 . Then the hydraulic pressure is released and the nut  103  and the plate  167  are removed. Finally, the hydraulic assembly  150  is removed and the installation of the next anchoring assemblies  125  can be started, until all four assemblies required per FIG. 3,  4  and  9  are installed. 
     Preferably, the centering collar  163  stays installed, one on each anchoring assembly  125  until the pile test is concluded and the anchoring assemblies  125  are removed. 
     As opposed to the conventional methods, whereby the anchor piles utilized in the testing remain in the ground and their tops must be sawed off, the reaction anchoring and support assemblies  125  are reusable. 
     The anchoring and support assemblies  125  are retrievable. They are retrieved from the earthen hole  126  utilizing the same hydraulic assembly they were installed with. 
     In order to retrieve the reaction anchor and support assemblies  125  from the earthen hole  126 , after the pile testing is completed, first the operator places the hydraulic assembly  150  once more over the rod  102 , by means of an on-site crane. Then the operator lowers the assembly down so that the rod  102  passes through the hole  155  on the bottom plate  152  and through the hole  156  of the top plate  153 . Now, the plate  167  is reinstalled, and the nut  103  is rethreaded down on the rod  102  and hand tightened against the plate  167 . 
     The operator then pumps hydraulic fluid through the lower inlets  157 , by means of the pump  159 . This forces the pistons  154  out of their respective cylinders  151 , slowly but forcefully pushing upwardly against the plates  153  and  167  and on the nut  103  which, being threaded onto the rod  102 , slowly lifts the rod  102  upwardly. This is done just enough to release the enormous pressure exerted by the nut  132  against the plate  130  at the time the anchor and support assembly  125  was installed. Now the operator threads the nut  132  upwardly on the rod  102  and then releases the pressure from the pump  159 , which releases the upward push of the pistons  154 . 
     Next the nut  103  and the plate  167  are removed, and the operator pumps again hydraulic fluid through the lower inlets  157 , by means of the pump  159 , to make the pistons  154  extend out of the cylinders  151  for a distance which is approximately equal to the distance the pistons  154  were extended during the process of installation. The hydraulic assembly then is lifted up again, by means of a crane, just enough, so that the top end of the rod  102  is below the plate  153 , in order to allow re-introducing the plate  167 , which now will be on top of the nut  132 , which has been threaded up. 
     Then, the operator lowers down the hydraulic assembly and sets its bottom plate  152  back on top of the plate  130  of the reaction anchor and support assembly  125  and with the rod  102  passing through the hole  156  of the top plate  153 . 
     The operator further threads up the nut  132  carrying the plate  167  upwardly until the plate  167  is against the bottom of the plate  153  with the nut  132  hand-tightened under it. 
     Now the operator pumps hydraulic fluid through the upper inlets  157 , which forces the pistons  153  back down, slowly but forcefully pushing downwardly on the nut  132 , which now is under the plates  167 ,  153  and is threaded onto the rod  102 . Therefore the pistons  154 , slowly yet powerfully, push the rod  102  down. Since the nut  168 , shown on FIG. 4, is threaded onto the rod  102  and it is on top and in contact with the frusto-cone  140 , it pushes the frusto-cone  140  also downwardly. By pushing the frusto-cone  140  downwardly, the compaction and consolidation pivoting plates  139  are effectively released from the powerful force which kept them pressed against the soil at the bottom of the earthen hole  126 . 
     With the pivoting plates  139  collapsed back down to a vertical position, now the hydraulic assembly can be finally removed, as previously described, after releasing the hydraulic pressure. 
     A job-site crane then is utilized for lifting the anchor and support assembly  125  out of the earthen hole  126 . Openings  131  on fins  129  are utilized for helping in lifting the assembly by means of devises and the job-site crane. 
     Referring now to FIG. 9, the reaction anchor and support assemblies  125 , utilized by the methods of the present invention, are shown in the process of testing a pile group  180  under a static axial load provided by the hydraulic assembly  145 . 
     The pile group  180  includes two or more single piles  182 . The pile group  180  is capped with a reinforced concrete cap  181  engineered and constructed specifically for the anticipated test loads. 
     The hydraulic cylinders  93  are set on the bearing plate  91 , with their respective pistons  94 , upon which the bearing plate  92  is set. The load cell  121  is set in between the bearing plate  92  and the bearing plate  122 . The bearing plates  91 ,  92  and  122  are of sufficient thickness to support the test loads provided by the hydraulic assembly  145  without bending, but not less than two inches thick. 
     The plate  122  bears against the flange  142  of I-beam assembly  116 . The I-beam assembly  116  bears against the I-beam assembly  115 , which is identical to the beam assembly  116 . The flanges  143  of the I-beam assembly  115  are set on top of the flanges  105  of I-beam assembly  116 . The beam assembly  115  is set at ninety degrees of the beam assembly  116  in the horizontal plane and on top of it. 
     The construction of the I-beam assemblies  115  and  116  of FIG. 9 is substantially the same as described in reference to FIGS. 3 and 4. The hydraulic assembly  145  of FIG. 9 also is substantially the same as described in reference to FIGS. 3 and 7. Nevertheless, for the pile group  180  testings, a larger axial load is required, for a larger capacity for the hydraulic cylinders  93 , with their respective pistons  94 , possibly, of larger diameter than it would be required for single pile testings. 
     The reaction anchor and support assemblies  125  of FIG. 9 are also substantially the same as described in reference to FIGS. 3,  4  and  5 . On occasion, a third pair of assemblies  125  is utilized in order to provide the reaction capacity required for the loading specified for a specific pile group test. 
     Continuing to refer to FIG. 9, the instrumentation set up is substantially similar to that described in reference to FIG.  3 . Nevertheless, for the group pile testing of FIG. 9, the dial gages  109  have their stems  118  connected to the top of the concrete cap. The dial gages  109  are connected to reference the beams  110  by means of the supports  147 . The stems  118  must have, at a minimum, two inches (5 Cm) of travel, must have a precision of at least 0.01 inches (0.25 millimeters) and must read to one sixty-fourth (1/64) of an inch. These dial gages provide the measurement of any longitudinal axial movement of the pile group  180  under the axial load provided by the hydraulic assembly  145 . Any axial movement beyond that specified, renders pile  90  unacceptable for its specified load. 
     Other instrumentation means are available for measuring other single pile and group pile movements under axial test loadings. 
     By the novel methods of the present invention, single piles or group piles are tested utilizing one, two, or more pairs of reaction anchor and support assemblies, as shown in FIGS. 3,  4 , and  9  and as described in the detailed description, instead of utilizing one, two, or more pairs of anchor piles which cannot be reutilized for future pile or pile group tests. 
     The testing process of the present invention does not depart from the procedures established by the A.S.T.M. standards for testing piles or pile groups. The novelty of this invention includes the utilization of the novel anchor and reaction anchoring and support assembly in combination with the novel I-beam assembly, with a built-in centering box. This combination, in addition to its reusability feature, is a safer and more reliable anchoring system than the conventional anchor piles utilized by the conventional methods. The mechanical connections between the conventional reaction beam and the conventional anchor piles of the conventional methods are substantially more susceptible to elongation under the axial pressures involved in the test than the Dywidag rod and Dywidag nuts combination utilized by this invention. 
     The component parts of the reaction anchor and support assembly of this invention have been utilized under axial loadings several times larger than the loads involved in pile tests. 
     The safety and reliability of the methods of this invention are demonstrated further by the anchoring method of this invention, which compacts and consolidates the soil it is anchored to, with the compaction and consolidation increasing, thus increasing the anchoring capacity, as the test loading increases. This can be understood readily by looking at the drawings in FIGS. 3,  5 , and  9 , showing the swingable pivoting plates anchored and pushing upwardly, at the bottom of an earthen hole, such that the more the test load pulls up on the Dywidag rod, the more powerfully the anchoring head gets anchored to the soil at the bottom of the hole. 
     The apparatus and method of the present invention substantially contrast with the conventional anchor piles, which depend absolutely on the friction between the pile and the soil into which it was hammered down. In the conventional application, the more the test load pulls the anchor pile up, the greater are the chances the pile will slide up, and often the piles do slide up. 
     As it can be seen by a review of the detailed description, the apparatus and method of the present invention accomplish all of its stated objectives. The apparatus and methods of the present invention are capable of modifications and variations without departing from the scope thereof. Accordingly, the detailed description and examples set forth above are meant to be illustrative only and are not intended to limit the scope of the invention as set forth in the appended claims.

Technology Classification (CPC): 4