Proposed Specifications for LRFD Soil-Nailing Design and Construction (2011)

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C-1 Introduction The pullout resistance database is presented in this appen- dix. The information consulted to build the pullout resistance database included the following: 1. Soil Nail Test Results • Load applied to the soil nail (P); • Total measured elongation (Δtot); • Observations made during test (e.g., premature failure, proximity to failure); and • Design Load (DL). 2. Soil Nail Data • Diameter of drill-hole (DDH); • Nail total length and bonded length (Ltot, LB); and • Nail bar diameter (DB). 3. Geotechnical Data • Site location; • Soil type description; • Geotechnical reports including boring logs; • Blow count (N) or other field test results; • Groundwater table location; • Plans with SNW and boring locations; • Description of nail installation method; and • Drawings and specifications of soil nails. Sources of Soil Nail Load-Test Data Soil nail load-test results were obtained from numerous sources including: the project team’s database; company mem- bers of ADSC: The International Association of Foundation Drilling; soil nail specialty contractors; state departments of transportation; and published data. A summary of the available data organized according to the material type, number of proj- ects, and number of tests used is presented in Table C-1. The soil nail load-test data was derived from proof load and verification tests. Over 95 percent of the data considered was derived from proof tests. For most cases, the maximum load applied to the nails was 150 percent of DL or less. An unexpected pullout failure, occurring before the intended load test level was achieved, was observed in only two proof tests. No unexpected pullout failure was observed in the verification tests before the intended load test level was achieved. The nominal bond resistance was established for the selected load tests using methods that are presented in the following subsection. Limitations noted in some of the tests listed in Table C-1 included inadequate or missing information related to (i) proj- ect features (e.g., tested nail not identified in plan or elevation views or correlated to a soil condition); (ii) geotechnical data (e.g., no geotechnical report, no boring logs, inadequate soil description); (iii) characteristics of test bars (e.g., missing infor- mation on DDH, bonded and unbonded lengths, bar diameter); and (iv) installation technique (e.g., information on drilling, casing, or grout strength characteristics were missing). When items listed in (i) through (iii) were missing, tests were excluded from the database. Additional results of soil nail testing may be used to increase design reliability. In theory, conducting more verification (pos- sibly testing nails to higher loads) should produce a higher degree of reliability in the design. Interpretation of Results The database was organized according to soil type (i.e., predominantly sand, clay, and weathered rock). The number of cases pertaining to sandy/gravelly soils was small (i.e., only eight cases); therefore, these data points were combined with those pertaining to sandy soils. In all cases, the bond stress was calculated based on the load (usually expressed in tons), bonded length, and drill-hole diameter. Alternatively, the pullout load per unit length, Q, (also previously referred to as load transfer, rPO) was calculated. The elastic elongation of the unbonded bar section was calculated and deducted A P P E N D I X C Soil Nail Test Pullout Resistance Database

C-2 from the total elongation to calculate the net elongation of the bonded length. The net elongation was then divided by the bonded length and the result expressed as a percentage. Load test results were plotted as mobilized bond stress, q, and expressed as a function of the total elongation, net elongation, or net elongation/bonded length (defined as the net elonga- tion divided by the bonded length, and expressed as a percent- age). The data was plotted against the total, net, or normalized net elongations. On average, the curves tended to flatten and exhibited the onset of ultimate conditions for a normalized net elongation of B = 0.1 to 0.5 percent (sands), 0.01 to 0.05 percent (clays), and greater than 0.5 percent (gravel and weathered rock). These trends are consistent with typical soil-strain response of these soil types. The data for sand tended to exhibit less variability when the load data was plotted as a function of the normalized net elongation. The interpretation of load-test results included the esti- mation of an “ultimate” nail load (equivalently, nominal bond resistance). Several procedures were used to estimate the nom- inal bond resistance, including: (a) field observations of “near” or imminent failure; (b) evaluation of test curves; (c) analyses of creep test data; and (d) analyses of loads using a maximum deflection criteria. The adequacy of each of these approaches is discussed below. Field Observations The success of this approach was limited because the great majority of tests were proof tests, which were loaded up to 150 percent of DL, and did not exhibit imminent failure. Con- tractors’ notes during load tests, if available, were reviewed. Evaluation of Test Curves This approach was helpful to estimate the elongation at which the test curve flattened and to establish an ulti- mate load. Observations provided better estimates of an ultimate condition when the soil nail test was performed in clays and clayey sands, when compared to tests in gravel, dense sands, and weathered rock. In the latter cases, soil nails typically required a significant deformation to mobi- lize their resistance. Analysis of Creep Test Data The usefulness of this approach was limited because none of the tests showed an excessive deformation rate that indi- cated an imminent load failure (or even a nail rejection in the U.S. practice). In French soil-nailing practice (Clouterre, 2002), deformation rates observed during creep tests at increasing loads are analyzed to estimate a “yield” pullout load. However, the amount of creep data that was available for this research project was insufficient for the Clouterre approach to be used. Analysis of Load-Elongation Curves Several criteria were used to analyze the load curves and establish an “ultimate” load. Techniques similar to those used to estimate the ultimate compression and tension loads in deep foundations were considered. Some of the techniques consid- ered included the well-known Davisson (1972) method (graph- ical estimation of an ultimate load from a load-settlement curve), the De Beer (1967and 1968) method (graphical estima- tion of ultimate loads based on the graphical representation of the logarithms of loads and settlements), and the Brinch- Hansen (1963) method (graphical estimation of ultimate loads based on a parabolic approximation of the load-settlement curve). Only in a few cases were these methods helpful to iden- tify clearly the ultimate pullout resistance. Methods commonly used in tension tests of piles were also considered to estimate the ultimate pullout load. In these methods (e.g., Hirany and Kulhawy, 2002; Koutsoftas, 2000), the ultimate load is achieved when the soil/nail interface shows 0.4 to 0.5 in. of movement. Predominant Material Type Number of Projects Number of Available Load Tests Number of Used Load Tests Sand 10 168 74 Sand/Gravel 3 31 8 Clay 8 92 45 Weathered Rock 5 67 26 Other 6 88 0 Total 32 446 153 Table C-1. Summary of available soil nail tests considered for database.

C-3 When the ultimate pullout resistance was not evident from the methods mentioned in items (a) through (d), the maximum load was considered to be achieved when the net is at least 1 in. This criterion is consistent with the practice adopted by some SNW contractors to stop a load test. Measured and Predicted Values of Pullout Resistance Measured values of pullout resistance were obtained based on the various criteria described above and are presented for each soil type. For each of these soil types, the predicted pullout resist- ance was defined as 200 percent of the design load as is com- mon in U.S. practice (see Byrne et al., 1998 and Lazarte et al., 2003). These estimations are also provided in Tables C-2 through C-4 for each soil type. Note that the predicted pull- out resistance values are not directly related to any specific design equation but, instead, represent the values selected by design engineers possibly based on a combination of recommended ranges (e.g., Elias and Juran, 1991) and val- ues based on local experience. Values predicted using cor- relations with PMT or SPT values were not used because PMT data was unavailable and because SPT information was incomplete or not directly associated to the soil nail test location. The mean, standard deviation, and COV of the bias were obtained for the lognormal distribution for each of the soil types. In establishing these parameters, the lognormal distri- bution was adjusted to match the lognormal distribution with the lower tail of the resistance bias data points. The statistical parameters for these curves are summarized in Table C-5. These factors are to perform the calibration of the pullout resistance factors.

No. Type of Natural Material Soil/RockType Project Location Test ID Bonded Length, LB (ft) Unbonded Length, LU (ft) Drill-Hole Diameter, DDH (in.) Nail Bar Diameter, DB (in.) Design Load, DL (kip) Test Design Load, DL (kip) Estimated Pullout Resistance, Q (kip/ft) Predicted Resistance (kips) Measured Resistance (kips) 1 Cohesionless Sand Milledgeville,GA 4 12 3 NA 1 24 24.0 2.0 48 29 2 Cohesionless Sand Milledgeville,GA 1 12 3 NA 1.25 24 24.0 2.0 48 31 3 Cohesionless Sand Milledgeville,GA 6 12 3 NA 1 24 24.0 2.0 48 33 4 Cohesionless Sand Milledgeville,GA Proof #1 5.2 9.3 6 0.75 9.8 9.8 1.88 19.6 14.3 5 Cohesionless Sandy Silt San Diego, CA 11 11 20 6 1.24 22 22 2.0 44 33 6 Cohesionless Sand Milledgeville,GA H-1-7 9 11 6 1 13.5 13.5 1.5 27 20.5 7 Cohesionless Sandy Silt San Diego, CA 8 11 18.5 6 1.24 22 22 2.0 44 34 8 Cohesionless Sandy Silt San Diego, CA 12 11 20 6 1.24 22 22 2.0 44 34.5 9 Cohesionless Sandy Silt San Diego, CA 9 11 20 6 1.24 22 22 2.0 44 35 10 Cohesionless Sandy Silt San Diego, CA 5 11.4 20 6 1.24 22.8 22.8 2.0 45.6 38 11 Cohesionless Sand Milledgeville,GA 2 12 3 NA 1 24 24.0 2.0 48 40 12 Cohesionless Sand Milledgeville,GA H-1-5 7.5 7.5 6 1 11.3 11.3 2 22.6 19.2 13 Cohesionless Sand Milledgeville,GA H-1-4 8 7 6 1 12 12 1.5 24 20.4 14 Cohesionless Sand Milledgeville,GA 5 12 3 NA 1 24 24.0 2.0 48 41 15 Cohesionless Sandy Silt San Diego, CA 7 11 20 6 1.24 22 22 2.0 44 38 16 Cohesionless Sand Milledgeville,GA H-1-2 5 10 6 1 7.5 7.5 1.5 15 13 17 Cohesionless Sandy Silt San Diego, CA 16 11.4 19 6 1.24 22.8 22.8 2.0 45.6 40 18 Cohesionless Sandy Silt San Diego, CA 21 11 20 6 1.24 22 22 2.0 44 39 19 Cohesionless Clayey Sand San Luis Obispo, CA D-1-2 16 4 3.5 0.875 15.8 25.28 1.6 50.56 45 20 Cohesionless Sandy Silt San Diego, CA 20 11.4 20 6 1.24 22.8 22.8 2.0 45.6 41 21 Cohesionless Sand Milledgeville,GA H-1-1 10 15 6 1 15 15 1.5 30 27 22 Cohesionless Clayey Sand San Luis Obispo, CA D-1-1 14 6 3.5 0.875 15.8 22.12 1.6 44.24 40 23 Cohesionless Sandy Silt San Diego, CA 18 11.4 19 6 1.24 22.8 22.8 2.0 45.6 41.5 24 Cohesionless Sand Roseville, CA D-2-1 10 12 6 0.875 18.1 18.1 1.8 36.2 33 25 Cohesionless Sandy Silt San Diego, CA 19 11.4 20 6 1.24 22.8 22.8 2.0 45.6 42 26 Cohesionless Sandy Silt San Diego, CA 17 11.4 19 6 1.24 22.8 22.8 2.0 45.6 42.5 27 Cohesionless Sand Milledgeville,GA 3 12 3 NA 1 24 24.0 2.0 48 45 28 Cohesionless Gravelly Sand Squaw Valley, CA D-4-3 10 10 3 1.181 29.23 29.23 2.9 58.46 55 29 Cohesionless Sand Milledgeville,GA H-2-1 5.2 9.3 6 0.75 9.8 7.8 1.5 15.6 14.8 Table C-2. Summary of estimation and prediction of nominal bond resistance—sands.

No. Type of Natural Material Soil/RockType Project Location Test ID Bonded Length, LB (ft) Unbonded Length, LU (ft) Drill-Hole Diameter, DDH (in.) Nail Bar Diameter, DB (in.) Design Load, DL (kip) Test Design Load, DL (kip) Estimated Pullout Resistance, Q (kip/ft) Predicted Resistance (kips) Measured Resistance (kips) 30 Cohesionless Clayey Sand San Luis Obispo, CA D-1-3 10 10 3.5 0.875 15.8 15.8 1.6 31.6 30 31 Cohesionless Sandy Silt San Diego, CA 15 11 19 6 1.13 27.5 27.5 2.5 55 53 32 Cohesionless Sandy Silt San Diego, CA 10 11 14 6 1.00 22 22 2.0 44 43 33 Cohesionless Sandy Silt San Diego, CA 14 11 19 6 1.13 27.5 27.5 2.5 55 54 34 Cohesionless Sand Milledgeville,GA H-1-3 7 13 6 1 10.5 10.5 1.5 21 21 35 Cohesionless Sandy Silt San Diego, CA 6 11.4 20 6 1.24 22.8 22.8 2.0 45.6 46 36 Cohesionless Sand Roseville, CA D-2-2 10 12 6 0.875 18.1 18.1 1.8 36.2 37 37 Cohesionless Gravelly Sand Squaw Valley, CA D-4-2 10 10 3 1.181 29.23 29.23 2.9 58.46 60 38 Cohesionless Sand Milledgeville,GA 7 12 3 NA 1 24 24.0 2.0 48 50 39 Cohesionless Sandy Silt San Diego, CA 13 11 19 6 1.00 22 22 2.0 44 46 40 Cohesionless Sand Milledgeville,GA H-1-6 4 16 6 1 6 6 1.5 12 13 41 Cohesionless Clayey Sand San Luis Obispo, CA D-1-4 10 10 6 1 15.8 15.8 1.6 31.6 35 42 Cohesionless Gravelly Sand Squaw Valley, CA D-4-6 10 10 3 1.181 29.23 29.23 2.9 58.46 65 43 Cohesionless Sandy Silt San Diego, CA 2 11.5 18.5 6 1.24 23 23 2.0 46 52 44 Cohesionless Sandy Silt San Diego, CA 22 11 6 6 1.24 22 22 2.0 44 50 45 Cohesionless Sandy Silt San Diego, CA 4 10.5 19.5 6 1.24 21 21 2.0 42 48 46 Cohesionless Sand Cobb, GA D-3-20 14.4 8.5 8 1.41 36.2 25.92 1.8 51.84 60 47 Cohesionless Sandy Silt San Diego, CA 23 11 6 6 1.24 22 22 2.0 44 51 48 Cohesionless Sandy Silt San Diego, CA 3 10.5 19.5 6 1.24 21 21 2.0 42 49 49 Cohesionless Sandy Silt San Diego, CA 1 10.5 18 6 1.24 21 21 2.0 42 50 50 Cohesionless Clayey Sand San Luis Obispo, CA D-1-6 10 24 6 1 15.8 15.8 1.6 31.6 38 51 Cohesionless Clayey Sand San Luis Obispo, CA D-1-8 10 25 6 1 15.8 15.8 1.6 31.6 39 52 Cohesionless Gravelly Sand Squaw Valley, CA D-4-8 10 10 2.5 1.181 20 20 2.0 40 50 53 Cohesionless Sand Cobb County, GA D-3-21 14.3 8.5 8 1.41 36.2 25.74 1.8 51.48 66 54 Cohesionless Gravelly Sand Squaw Valley, CA D-4-1 10 10 3 1.181 29.23 29.23 2.9 58.46 77 55 Cohesionless Gravelly Sand Squaw Valley, CA D-4-4 10 10 3 1.181 29.23 29.23 2.9 58.46 79 56 Cohesionless Gravelly Sand Squaw Valley, CA D-4-5 10 10 3 1.181 29.23 29.23 2.9 58.46 80 57 Cohesionless Clayey Sand San Luis Obispo, CA D-1-5 10 10 6 1 15.8 15.8 1.6 31.6 44 58 Cohesionless Gravelly Sand Squaw Valley, CA D-4-7 10 10 2.5 1.181 20 20 2.0 40 57 Table C-2. (Continued). (continued on next page)

No. Type of Natural Material Soil/RockType Project Location Test ID Bonded Length, LB (ft) Unbonded Length, LU (ft) Drill-Hole Diameter, DDH (in.) Nail Bar Diameter, DB (in.) Design Load, DL (kip) Test Design Load, DL (kip) Estimated Pullout Resistance, Q (kip/ft) Predicted Resistance (kips) Measured Resistance (kips) 59 Cohesionless Clayey Sand San Luis Obispo, CA D-1-7 10 10 3.5 0.875 15.8 15.8 1.6 31.6 46 60 Cohesionless Sand Cobb County, GA D-3-27 15.7 7.8 8 1.41 36.2 28.26 1.8 56.52 85 61 Cohesionless Sand Cobb County, GA D-3-30 17.4 6 8 1.41 36.2 31.32 1.8 62.64 95 62 Cohesionless Sand Cobb County, GA D-3-26 14.75 8.5 8 1.41 36.2 26.55 1.8 53.1 83 63 Cohesionless Sand Cobb County, GA D-3-17 14.8 15.2 8 1.41 36.2 26.64 1.8 53.28 84 64 Cohesionless Sand Cobb County, GA D-3-16 14.5 12.5 8 1.41 36.2 26.1 1.8 52.2 84 65 Cohesionless Sand Cobb County, GA D-3-10 15.9 7.3 8 1.41 36.2 28.62 1.8 57.24 94 66 Cohesionless Sand Cobb County, GA D-3-28 14.2 8.5 8 1.41 36.2 25.56 1.8 51.12 86 67 Cohesionless Sand Cobb County, GA D-3-22 11 4 8 1.41 36.2 19.8 1.8 39.6 68 68 Cohesionless Sand Cobb County, GA D-3-18 14 8.5 8 1.41 36.2 25.2 1.8 50.4 89 69 Cohesionless Sand Cobb County, GA D-3-24 12.3 4.5 8 1.41 36.2 22.14 1.8 44.28 79 70 Cohesionless Sand Cobb County, GA D-3-19 15.3 9.7 8 1.41 36.2 27.54 1.8 55.08 100 71 Cohesionless Sand Cobb County, GA D-3-9 15 7.5 8 1.41 36.2 27 1.8 54 100 72 Cohesionless Sand Cobb County, GA D-3-23 14.8 8 8 1.41 36.2 26.64 1.8 53.28 100 73 Cohesionless Sand Cobb County, GA D-3-33 11 4 8 1.41 36.2 19.8 1.8 39.6 75 74 Cohesionless Sand Cobb County, GA D-3-4 14.5 7.3 8 1.41 36.2 26.1 1.8 52.2 100 75 Cohesionless Sand Cobb County, GA D-3-25 14.2 11.5 8 1.41 36.2 25.56 1.8 51.12 100 76 Cohesionless Sand Cobb County, GA D-3-32 14 9 8 1.41 36.2 25.2 1.8 50.4 100 77 Cohesionless Sand Cobb County, GA D-3-14 12.4 16.7 8 1.41 36.2 22.32 1.8 44.64 90 78 Cohesionless Sand Cobb County, GA D-3-13 13.5 3.2 8 1.41 36.2 24.3 1.8 48.6 99 79 Cohesionless Sand Cobb County, GA D-3-6 13.5 7 8 1.41 36.2 24.3 1.8 48.6 100 80 Cohesionless Sand Cobb County, GA D-3-12 13.2 3.6 8 1.41 36.2 23.76 1.8 47.52 99 81 Cohesionless Sand Cobb County, GA D-3-11 12.2 4.5 8 1.41 36.2 21.96 1.8 43.92 93 82 Cohesionless Sand Cobb County, GA D-3-29 9.1 6 8 1.41 36.2 16.38 1.8 32.76 70 Table C-2. (Continued).

No. Type of Natural Material Soil Type Location Test ID Bonded Length, LB (ft) Unbonded Length, LU (ft) Drill- Hole Diameter, DDH (in.) Nail Bar Diameter, DB (in.) Design Load, DL (kips) Test Design Load, DL (kips) Estimated Pullout Resistance, Q (kips/ft) Predicted Resistance (kips) Measured Resistance (kips) 1 Fine-grained Sandy Clay San Luis Obispo, CA D-5-1 11 18 6 1(6) 15.8 17.6 1.6 35.2 31 2 Fine-grained Sandy Clay San Luis Obispo, CA D-5-2 13 13 6 0.875 15.8 20.8 1.6 41.6 37 3 Fine-grained Clay Solana Beach, CA D-6-1 15.3 6.5 8 1 22 16.83 1.1 33.66 31 4 Fine-grained Clay Solana Beach, CA D-6-2 17 4 8 1 22 18.7 1.1 37.4 35.7 5 Fine-grained Clay Solana Beach, CA D-6-3 16 7.5 8 1 22 17.6 1.1 35.2 33.8 6 Fine-grained Clay Solana Beach, CA D-6-4 16.75 6.5 8 1 22 18.425 1.1 36.85 35.6 7 Fine-grained Clay Solana Beach, CA D-6-5 16.8 6.5 8 1 22 18.48 1.1 36.96 35.9 8 Fine-grained Clay Solana Beach, CA D-6-6 15.4 6.5 8 1 22 16.94 1.1 33.88 33.0 9 Fine-grained Clay Solana Beach, CA D-6-7 16.4 12.5 8 1 22 18.04 1.1 36.08 35.4 10 Fine-grained Clay Solana Beach, CA D-6-8 15.25 13.5 8 1 22 16.775 1.1 33.55 33.0 11 Fine-grained Clay Solana Beach, CA D-6-9 13 14 8 1 22 14.3 1.1 28.6 28.3 12 Fine-grained Clay Guadalupe River, CA D-10-20 10 15 8 0.875 13.6 13.6 1.4 27.2 27 13 Fine-grained Clay Solana Beach, CA D-6-10 13 8 8 1 22 14.3 1.1 28.6 28.5 14 Fine-grained Clay Solana Beach, CA D-6-11 14.5 12 8 1 22 15.95 1.1 31.9 31.9 15 Fine-grained Clay Solana Beach, CA D-6-12 14.2 8.8 8 1 22 15.62 1.1 31.24 31.4 16 Fine-grained Clay Solana Beach, CA D-6-13 14.2 9.3 8 1 15.6 15.62 1.1 31.24 31.6 17 Fine-grained Clay Solana Beach, CA D-6-14 15 8.2 8 1 22 16.5 1.1 33 33.5 18 Fine-grained Clay Solana Beach, CA D-6-15 15.4 17.8 8 1 22 16.94 1.1 33.88 34.6 19 Fine-grained Clay Solana Beach, CA D-6-16 16.75 6.5 8 1 22 18.425 1.1 36.85 37.8 20 Fine-grained Clay Solana Beach, CA D-6-17 12 10.5 8 1 22 13.2 1.1 26.4 27.2 21 Fine-grained Clay Solana Beach, CA D-6-18 15.5 7.7 8 1 22 17.05 1.1 34.1 35.3 22 Fine-grained Clay Solana Beach, CA D-6-19 15.5 8 8 1 22 17.05 1.1 34.1 35.5 23 Fine-grained Clay Solana Beach, CA D-6-20 17.8 5 8 1 22 19.58 1.1 39.16 40.9 24 Fine-grained Clay Solana Beach, CA D-6-21 17.3 5.7 8 1 22 19.03 1.1 38.06 40.0 25 Fine-grained Clay Solana Beach, CA D-6-22 16.8 6.25 8 1 22 18.48 1.1 36.96 39.0 26 Fine-grained Clay Solana Beach, CA D-6-23 17.25 5.7 8 1 22 18.975 1.1 37.95 40.2 Table C-3. Summary of estimation and prediction of nominal bond resistance—fine-grained soils. (continued on next page)

No. Type of Natural Material Soil Type Location Test ID Bonded Length, LB (ft) Unbonded Length, LU (ft) Drill- Hole Diameter, DDH (in.) Nail Bar Diameter, DB (in.) Design Load, DL (kips) Test Design Load, DL (kips) Estimated Pullout Resistance, Q (kips/ft) Predicted Resistance (kips) Measured Resistance (kips) 27 Fine-grained Clay Solana Beach, CA D-6-24 16.8 6 8 1 22 18.48 1.1 36.96 39.4 28 Fine-grained Clay Guadalupe River, CA D-10-8 7.5 15 8 0.875 13.6 10.2 1.4 20.4 22 29 Fine-grained Clay Guadalupe River, CA D-10-2 10 20 6 0.875 13.6 13.6 1.4 27.2 30 30 Fine-grained Clay Guadalupe River, CA D-10-9 10 15 8 0.875 13.6 13.6 1.4 27.2 31 31 Fine-grained Clay Guadalupe River, CA D-10-19 10 15 8 0.875 13.6 13.6 1.4 27.2 32 32 Fine-grained Silty Clay Chattanooga, TN 1 8 NA 6 1 16 16 2.0 32 38 33 Fine-grained Clay Guadalupe River, CA D-10-1 10 20 6 0.875 13.6 13.6 1.4 27.2 33 34 Fine-grained Clay Guadalupe River, CA D-10-5 10 15 8 0.875 13.6 13.6 1.4 27.2 33.5 35 Fine-grained Clay Guadalupe River, CA D-10-6 10 15 8 0.875 13.6 13.6 1.4 27.2 34 36 Fine-grained Clay Guadalupe River, CA D-10-3 10 20 6 0.875 13.6 13.6 1.4 27.2 35 37 Fine-grained Clay Guadalupe River, CA D-10-13 10 15 8 0.875 13.6 13.6 1.4 27.2 36 38 Fine-grained Clay Guadalupe River, CA D-10-4 10 15 8 ` 13.6 13.6 1.4 27.2 37 39 Fine-grained Clay Guadalupe River, CA D-10-7 10 15 8 0.875 13.6 13.6 1.4 27.2 38 40 Fine-grained Sandy Lean Clay San Luis Obispo, CA D-5-4 10 10 6 0.875 15.8 16 1.6 32 46 41 Fine-grained Clay Guadalupe River, CA D-10-10 10 15 8 0.875 13.6 13.6 1.4 27.2 40 42 Fine-grained Clay Guadalupe River, CA D-10-11 10 20 8 0.875 13.6 13.6 1.4 27.2 41 43 Fine-grained Clay Guadalupe River, CA D-10-14 10 15 8 0.875 13.6 13.6 1.4 27.2 42 44 Fine-grained Clay Guadalupe River, CA D-10-17 10 15 8 0.875 13.6 13.6 1.4 27.2 43 45 Fine-grained Clay Guadalupe River, CA D-10-16 10 15 8 0.875 13.6 13.6 1.4 27.2 44 Table C-3. (Continued).

No. Type of Natural Material Soil Type Location Test ID Bonded Length, LB (ft) Unbonded Length, LU (ft) Drill- Hole Diameter, DDH (in.) Nail Bar Diameter, DB (5) (in.) Design Load, DL (kips) Test Design Load, DL (kips) Estimated Pullout Resistance, Q (kips/ft) Predicted Resistance (kips) Measured resistance (kips) 1 Rock Mélange Marin County, CA D-8-10 15 5 6 NA 27.1 40.5 2.7 81 55 2 Rock Mélange Marin County, CA D-7-5 10 10 6 1 34 34 3.4 68 47 3 Rock Mélange Marin County, CA D-7-4 10 10 6 1 34 34 3.4 68 50 4 Rock Mélange Marin County, CA D-7-3 10 10 6 1 34 34 3.4 68 53 5 Rock Mélange Marin County, CA D-8-1 9 15 6 NA 27.1 24.3 2.7 48.6 40 6 Rock Mélange Marin County, CA D-8-3 10 10 6 NA 27.1 27 2.7 54 47 7 Rock Mélange Marin County, CA D-7-6 10 10 6 1 34 34 3.4 68 62 8 Rock Mélange Marin County, CA D-7-1 10 10 6 1.27(6) 34 34 3.4 68 65 9 Rock Mélange Marin County, CA D-7-2 10 10 6 1.27(6) 34 34 3.4 68 67 10 Rock Shale Pike County, KY P-1-7 9.8 26.2 4 1.27 42.15 42.14 4.3 84.28 84 11 Rock Mélange Marin County, CA D-8-12 10 19 6 NA 27.1 27 2.7 54 54 12 Rock Shale Pike County, KY P-1-2 9.8 29.5 4 1.27 42.15 42.14 4.3 84.28 85 13 Rock Mélange Marin County, CA D-8-5 10 10 6 NA 27.1 27 2.7 54 55 14 Rock Shale Pike County, KY P-1-8 9.8 19.7 4 1.27 42.15 42.14 4.3 84.28 86 15 Rock Shale Pike County, KY P-1-1 9.8 26.2 4 1.27 42.15 42.14 4.3 84.28 88 16 Rock Shale Pike County, KY P-1-5 9.8 19.7 4 1.27 42.15 42.14 4.3 84.28 89 17 Rock Shale Pike County, KY P-1-3 9.8 31.2 4 1.27 42.15 42.14 4.3 84.28 90 18 Rock Shale Pike County, KY P-1-6 9.8 31.2 4 1.27 42.15 42.14 4.3 84.28 91 19 Rock Shale Pike County, KY P-1-4 9.8 14.8 4 1.128 42.15 42.14 4.3 84.28 94 20 Rock Shale Pike County, KY P-1-10 9.8 4.9 4 1.27 42.15 42.14 4.3 84.28 95 21 Rock Mélange Marin County, CA D-8-6 9 17 6 NA 27.1 24.3 2.7 48.6 55 22 Rock Shale Pike County, KY P-1-9 9.8 29.5 4 1.27 42.15 42.14 4.3 84.28 99 23 Rock Shale Pike County, KY P-1-12 9.8 19.7 4 1.27 42.15 42.14 4.3 84.28 102 24 Rock Mélange Marin County, CA D-8-4 9 11 6 NA 27.1 24.3 2.7 48.6 60 25 Rock Shale Pike County, KY P-1-11 9.8 4.9 4 1.27 42.15 42.14 4.3 84.28 105 26 Rock Mélange Marin County, CA D-8-2 7 13 6 NA 27.1 18.9 2.7 37.8 48 Table C-4. Summary of estimation and prediction of nominal bond resistance—rock.

C-10 References Brinch-Hansen, J. (1963). “Discussion of ‘Hyperbolic Stress-Strain Response: Cohesive Soils,’ ” Journal for Soil Mechanics and Foun- dation Engineering, American Society of Civil Engineers, Vol. 89, No. 4, pp. 241–242. Byrne, R. J., D. Cotton, J. Porterfield, C. Wolschlag, and G. Ueblacker (1998). “Manual for Design and Construction Monitoring of Soil Nail Walls.” Report FHWA-SA-96-69R, Federal Highway Administration, Washington, D.C. Clouterre (2002). “Additif 2002 aux recommandations Clouterre 1991” (Trans.: 2002 Addenda to Recommendations Clouterre 1991), In French, Presses de l’Ecole Nationale des Ponts et Chaussées, Paris, France. Davisson, M. T. (1972). “High Capacity Piles,” Proceedings of Lecture Series on Innovations in Foundation Construction, American Society of Civil Engineers, Illinois Section, Chicago, pp. 81–112. DeBeer, E. E. (1967 and 1968) “Proefondervindlijke bijdrage tot de studie van het grensdraag vermogen van zand onder funderingen op staal.” Tijdshift der Openbar Verken van Belgie, No. 6 (1967) and No. 4, 5, and 6 (1968). Elias, V. and I. Juran (1991). “Soil Nailing for Stabilization of Highway Slopes and Excavations.” Publication FHWA-RD-89-198, Federal Highway Administration, Washington D.C. Hirany, A. and F.H. Kulhawy (2002). “On the Interpretation of Drilled Foundation Load Test Results.” In Deep Foundations 2002 (GSP 116), M.W. O’Neill and F.C. Townsend (Eds.), ASCE, Reston, VA., pp. 1018–1028. Koutsoftas, D.C. (2000). “High Capacity Steel H-Piles in Franciscan Rock.” In Proceedings of Geo-Denver 2000, Denver, Colorado, August 5-8, N.D. Dennis, Jr., R. Castelli, and M.W. O’Neill (Eds.), ASCE, Reston, VA, pp. 158-177. Lazarte, C. A., V. Elias, R. D. Espinoza, and P. J. Sabatini (2003). “Soil Nail Walls.” Geotechnical Engineering Circular No. 7, Pub- lication FHWA-IF-03-017, Federal Highway Administration, Washington, D.C. Resistance Parameters Number of Points in Database Mean of Bias Standard Deviation Coefficient of Variation Log Mean of Bias Log Standard Deviation Material N Distribution Type λ R σ R COV R μ ln σ ln Sand and Sand/Gravel 82 Lognorm al 1.050 0.25 0.24 0.02 0.24 Fine - Grained 45 Lognorm al 1.033 0.05 0.05 0.03 0.05 Rock 26 Lognorm al 0.920 0.18 0.19 -0.10 0.19 All 153 Lognorm al 1.050 0.22 0.21 0.03 0.21 Table C-5. Statistics of bias for nominal bond strength.