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Guilarte Residence-Claim No.354110 ' HCE Report No. 100091.1 Page No. 10 Our investigation is not of sufficient scope to develo a remediation plan for the non-sinkhole identified cause(s) of damage. RECO MENDATIONS i i T ical re airs for sinkhole dama e involve compa tion grouting at the top of the limestone formation,followed YP P g b re eated injection of grout through the soil layer above the limestone. The purpose of compaction grouting Y P is to seal voids in the limestone formation and coinp ct soils loosened by the downward vertical raveling into the voids in the limestone. Where settlement of the sla and foundation has occurred due to the presence of sinldiole activity,compaction grouting frequently restores th slab and foundation to near original construction elevations. However,while this is a desirable effect,there is n certainty that compaction grouting will reverse inovements that have already occurred. We recommend compaction grouting be performed round the perimeter of the house utilizing alternating vertical and angled grout injection holes. The holes should xtend through the overburden soils and be tenninated in the limestone formation. The angled holes should be irected below the stnicture, and the vertical holes placed as close as practically possible to the structure. Verti al and angled grout holes should be spaced on approximate 10-foot centers. A Coinpaction Grouting Specification (A endix ) and Preliininary Grout Hole Location Plan (�pendix G, Fi�an�e 1)are attached. These should be used as a uide for ground modification contractors. This specification should be used to assist the grouting contractor wi i pricing and preparation of a work scope. Contractors may inodify the work scope and suggest alternate scope as they feel appropriate. All inodifications to the suggested work scope inust be approved by the geotechnicai ngineer prior to commenceinent of worlc. ' ween a roximatel We estimate that approxunately 1,300 lmear feet f grout hole casmg will be mstalled bet pp y ' 16 grout holes. We also estimate that a total of ap roximately 225 cubic yards of grout will be injected into the grout holes. These estiinates are provided to assist ontractors with the planning of the work scope and obtaining permitting. We do not know what the final number of grout holes will be,nor do we do not lcnow how deep each grout hole will go. We also do not know how in h grout will need to be injected into each hole. The actual ainount of casing installed and grout injected inay significantly differ from these estimates. The compaction grouting process will compress an compact overburden soils below the home. These soils will contain water which is trapped temporarily duri g the grouting process. This water, known as hydrostatic pressure,takes time to dissipate. As it dissipates,tl e soil zone containing the elevated hydrostatic water pressure will continue to compress. Althotigh hydrostatic ater pressure usually dissipates within 3 to 4 weeks, clayey soils and organic soils may have much longer stabil zation durations. At the Guilarte residence,we anticipate that significant cosmetic damage may occur after rep irs are perfoi7ned if a 4-week delay between grouting and cosmetic repairs is not observed. Based on the quautities of casing and compaction�rout projected to reinediate sinkhole activity at tl�is site,we estimate that the project will require 12 work days t complete. Costs for grout injection are estimated as follows: 1Vlobilization: $ 2,500 Casing Installation: ,300 linear feet @$17/ft $22,100 Grout Injection: 25 cubic yards @$170/yd $38,250