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� Guilarte Residence-Claim No.354110 HCE Report No. 100091.1 Page No.4 or electrical resistivity iinaging (ERI). The engin er will utilize his knowledge of local subsurface conditions, site conditions,and information obtained through ublicly available records to select the proper geophysical tool for the site. The geophysical tools provide large a ea coverage of the site and help the engineer select locations for fiiture invasive,direct sainpling. The geophys cal tools are analogous to ultra-sound,x-ray or MRI inedical procedures that doctors use. The geophysical tools rovide a subsurface iinage that can be interpreted by a trained engineer or geologist. Frequently,the geophysic 1 testing will identify soine unusual condition relative to the overall background condition. This unusual coiid'tion relative to the background conditions is usually referred to as a feature or an anoinaly. Feattires may be ca sed by sinkholes,buried tree stumps,buried utilities,fonner stream beds,previous excavation activities and/or numerous other sources. The geophysical equipinent is used as a screening tool to aid the selection of borin locations to target features as well as to evaluate normal background conditions. Using the geophysical exploration results, the en ineer selects locations for invasive testing. Invasive testing usually involves Standard Penetration Test(SPT) orings or Cone Penetration Test(CPT)soundings. The SPT and CPT techniques require boring into the groun to collect and obtain relative strength data of soil samples or pushing a probe into the ground to ineasure physi al soil properties,respectively. If necessary,laboratory tests are perfonned to further define the physical prop rties of representative soil sainples. In addition to the SPT or CPT borings,shallow au er borings are commonly performed. The auger borings may be placed close to the structure to gather addition 1 data about the site preparation and soils present at the edge of the structure,or at other locations such as those closer to the foundation than can be accessed with the SPT or CPT rigs. As a matter of routine,a test pit is pe nned adjacent to one exterior wall of the strucriire to expose the foundation system. The depth, width and liysical condition of the foundation are also recorded for evaluation. The data froin the invasive testing is compared ith the geophysical suivey data and the laboratory tests. The engineer considers the collected soil infonnation the stnicture condition, dainage patterns, and historical and publicly available data and possibly additional av ilable infonnation to develop an opinion about the sinlcholes as a cause of damage. If the evahiation results in negative conchision regarding sinkhole activity as a cause of structure damage,then alternate likely causes of amage are presented. Coimnonly, structure damage is caused by the presence of poor soil conditions such as eat, debris, or unsuitable fill below the structure. Nuinerous possibilities exist. If the evaluation results in a ositive conchision regarding sinkhole activity as a cause of dainage,then a reinedial repair plan or other cou se of action is provided in the report conclusions. Field Methods The procedures used by HCE for field testing are in general accordance with industry standards of care, established geotechiiical engineering practices and Ainerican Society for Testing and Materials (ASTM) 'standards. The exploration consisted of perfoi ing a Ground Penetrating Radar (GPR) survey around the perimeter of the house and within the interior of he residence. After reviewing the results of the GPR suivey, four(4) Standard Penetration Test(SPT)borings were perfonned to depths of 58 feet 9 inches, 59 feet, 73 feet 10 inches, and 79 feet 5 inches below the exis ing ground surface. In addition, a Floor Level Survey was performed on the interior, and two (2) shallow a iger borings, and two (2) test pits were performed around the periineter of the house. The borings and test pi s were perfonned at the approxiinate locations shown on the attached Location Plan. Descriptions of each fi ld test method and the results of the tests are presented in the following sections.