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Guilarte Residence-Claim No.354110 HCE Report No. 100091.1 Page No. 9 EVA UATION Definition of Sinkholes This exploration was perfoi-�ned with an einphasis o sinkhole development as a cause of ground subsidence. Sinkholes have typical characteristics which include ones of very soft or loose soil sediments that have washed downward into pre-existing cavern networks within t�ie bedrock. This very soft or loose soil zone is corrunonly called a raveling zone. The raveling zone originat s at the limestone surface as the overlying soils begin to collapse or inove vertically downward into the soluti n features within the liinestone. The loosening occurs in an upward vertical inotion until subsidence of the gr und surface occurs. The essential criteria for establishing the presence of sinkhole development as a probable ause of subsidence and structural damage include; • A cylindrical or cohimnar zone of very sof or loose soil that extends from the top of the limestone fonnation to the ground surface. • The presence of significant voids within the imestone. • A complete loss of drilling fluid circulation in the over-burden soils at significant distance above the liinestone fonnation. • A loss of soil density with increasing depth f penetration,generally observed for a distance of tens of feet. (the loss of soil density with increasing depth of penetration should be represented by a trend and not isolated individual samplings). • Stnicture dainage, a surface ground depre sion or other obvious observable indications of ground inovement inust be present in the immediate 1 cation. Generally when a structure is affected by sinkhole activity,the dainage is concentrated in speci ic areas and not widespread. The presence of one of the individual characteristic above does not establish reasonable evidence of damage caused by sinkhole. Damage caused by sinkholes m ist include multiple criteria from above. Site Specific Conclusions The results of our exploration and the SPT borings p rfonned at this site encountered conditions consistent with the definition of sinkholes as described in the criteria rovided in the previous section of this report. SPT borings B-3,and B-41ost complete drilling fluid circulation at ignificant depths(21 and 32 feet)above the hard limestone foi7nation,which can be an indication of downward ra eling ofthe overburden soils. SPT boring B-1 experienced a slight loss of density with depth froin a depth of 23 to 48 feet,with N-values generally decreasing froin 23 to 2 blows per foot. The floor level survey showed that small amount of subsidence inay have occurred at the right rear corner of the structure. Based on the results of this exploration,it is our pr fessional opinion that sinkhole activity can not be ruled out as a possible contributing factor to damag at this residence, within a reasonable professional probability. The cracks in the driveway and front porch tile,as we 1 as the hairline cracks in the terrazzo floor,are apparently the result of concrete shrinkage,which is common an occurs when concrete shrinks as it dries/cures. There are not adequate control joints in the driveway. Contro' joints are typically placed in concrete slabs to provide a location for shrinkage cracics to occur. Control jo nts should be spaced no fiirther than 8 feet apart in the horizontal and vertical directions of concrete slabs.