FINAL PROJECT REPORT

Transcription

1 CE788: Geotechnical Engineering Testing (Spring 2015) FINAL PROJECT REPORT Submitted By Al Naddaf, Mahdi Abbas Mahdi Jiang, Yan Mohammed, Hemim Jalal Neupane, Madan Submitted to Jie Han, Professor Due Date 05/12/2015

2 Table of Contents Table of Contents Acknowledgments Executive Summary Introduction Physical Conditions Climate Topography and Drainage Regional Geology and Seismicity Soil Survey Mapping Sub-surface Conditions Field Exploration Bore Hole Preparation Drilling and Sampling Standard Penetration Test (SPT) Vane Shear Test Pressure Meter Test

3 4.6 Direct Push Bull Sampling Laboratory Testing Specific Gravity Determination Grain Size Distribution of Soil Atterberg Limit Determination Consolidation of Sample Unconfined Compression Test Consolidated Undrained Test Foundation Recommendations Foundation Design Recommendation Foundation Construction Considerations Conclusions and comments References Appendix B: Boring log Sheet Appendix C: Field Test Data Sheet Appendix D: Lab Test Data Sheet Appendix F: The Calculation of Vertical Bearing Capacity of a Single Pile

4 14. Appendix G: The Calculation of settlement of a Single Pile List of Tables Table 3-1 Lawrence Climate. (Places, 2015)... 8 Table 3-2 Subsurface Conditions Table 4-1 Location of Boreholes, Types of Digging and Activities Performed Table 4-2 SPT Measured and Corrected N Values and Other Outcomes Table 4-3 Vane Shear Test Results Table 4-4 Result from Pressuremeter Test Table 5-1 Results from 1-D Consolidation Test Table 5-2 Results from CU Test Table 6-1Recommended pile foundation

5 List of Figures Figure 3-1 Lawrence Climate (Places, 2015)... 9 Figure 3-2 Boreholes locations Figure 3-3. Micro-earthquakes (*) and faults (/) in Kansas (Burchett, Luza, Van Eck, & Wilson, 1983) Figure 3-4. Pattern of Soils in Martin-Sogn-Vinland Association in Douglas County, KS (Deckey, Zimmerman, Plinsky, & Davis, 1977) Figure 4-1: Test Site Location and Demarcation Figure 4-2: Drill Hole Preparation by Removing Top Paved Part Figure 4-3 Location of Shelby Tube Sampling Figure 4-4 Location of Standard Penetration Test at Different Boreholes Figure 4-5 Volume and Pressure Calibration of Pressuremeter Figure 4-6 Corrected Pressuremeter Curve Showing Elastic Range and Plastic Range Figure 5-1 Gradation Curve of the Sampled Soil Figure 5-2 Void Ratio versus Pressure Curve (Log Scale) Figure 5-3 Taylor`s root time method

6 Figure 5-4 Casagrande's log t Method Figure 5-5 Stress versus Strain Curve of Unconfined Compression Test Figure 5-6 Deviator Stress versus Strain Curve of CU Test Figure 5-7 Normal Stress versus Axial Strain Curve Figure 5-8 Mohr Column Failure Envelope Figure 6-1 Soil profile for the design of the piled foundation Figure 9-1. KU Central District Plan (dcm.ku.edu) Figure 9-2. Site Location Plan Figure 9-3. Borings Location plan Figure 9-4. Topography map of Test Location (3) Figure Subsurface Exploration and Sampling Sheet ( 19 feet depth) Figure Subsurface Exploration and Sampling Sheet (>19 feet depth)

7 1. Acknowledgments Thanks to Kansas department of transportation (KDOT) for providing the necessary equipment for the tests were conducted for this report. Thanks to CEAE department also for the facilities they provided for this report. 2. Executive Summary A geotechnical investigation has been conducted for a two-storey building close to Burge Union. Based on the information from the subsurface exploration, field in-situ tests, and lab tests, the following geotechnical summaries were given: From the field test, the undrained shear strength of the foundation soil was very high. The undrained shear strength were an average of 72 kpa from SPT test, 92.4 kpa from Vane shear test (undisturbed) and 71 kpa from pressruemeter test. This result was supported by the laboratory test as the unconfined compressive gives the undrained shear strength of 94.8 kpa. So, the foundation is strong enough to support probable foundation. Also, from consolidation test, it was found that the filed was over consolidated. Also, the permeability of the soil is very small. 3. Introduction This report presents the results of the subsurface exploration and geotechnical engineering services performed for a new construction planned to be located at the Child Care Drive, west of Burge Union, at the campus of University of Kansas (KU), Lawrence, Kansas, as shown in 6

8 Appendix A-Figure 7 and Figure 8. The purpose of these exploration and geotechnical engineering services is to provide information and geotechnical engineering recommendations relative to: Subsurface soil conditions Groundwater conditions Foundation design and construction Estimated seismic site class Earthwork Construction considerations Lateral earth pressures The geotechnical scope of work for this project included the advancement of five boreholes, only three of them were conducted to a depth about 17½ ft below the existing grade in the area of the proposed new construction, as shown in Appendix A-Figure 9 The boreholes were conducted by a geotechnical group of KDOT using their advanced equipment for testing and analyzing a geotechnical characteristics of the soil at that location. In this context, the graduate students at CE 788 class in the school of engineering at KU conducted a laboratory tests on the Shelby tube samples were extracted from the boreholes. The students were divided into three groups. Group 2 performed four types of geotechnical tests: Atterberg limit test, hydrometer test, one dimensional consolidation test, and Consolidation undrained triaxial test on the samples were pulled out from the borehole number 4 by Shelby tube number 2 and 5. 7

9 4. Physical Conditions 3.1. Climate The climate of Lawrence, where the exploration and geotechnical engineering services were conducted, gets more than 39 inches of rain per year, while the US average is 37 (Data, n.d.). Snowfall is 13 inches, while the average US city gets 25 inches of snow per year, as shown in the Table 1 and Figure 1. On average, there are 211 sunny days per year in Lawrence. The highest temperature in July is around 90 degrees. The January low is 18. Comfort index, which is based on humidity during the hot months, is a 30 out of 100, where higher is more comfortable. The US average on the comfort index is 44 (Places, 2015). Table 4-1 Lawrence Climate. (Places, 2015) Climate\Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Average high ( F) Average low ( F) Avg. Precipitation (inch) Average snowfall (inch) Annual Avg

10 Figure 4-1 Lawrence Climate (Places, 2015) 3.2. Topography and Drainage The test location is located at 880 to 890 ft above sea level (pickatrail, n.d.), as shown in Appendix A-Figure 10. The area, where the borings were conducted, was almost level. The borings were in the park lot, which is paved by a 5.75 inches flexible pavement, as shown in Figure 2. The boring area has a good drainage through the drain pipes were transfer the rainfall water to the nearby opened drain channel. 9

11 Figure 4-2 Boreholes locations 3.3. Regional Geology and Seismicity The most seismic activate area in Kansas is along and parallel to the Humboldt fault zone. In the northern part of this zone, micro earthquakes and felt earthquakes near Manhattan are associated with the Humboldt zone itself. The second most active area is a northeast-southeast-trending zone near the Nebraska border in Washington, Republic, and cloud Counties, as shown in Figure 3 (Burchett, Luza, Van Eck, & Wilson, 1983). The largest earthquake in Kansas was Manhattan earthquake, which was happened in April 24, 1867 Measuring 5.1 on the Richter scale. This earthquake caused several minor injuries, cracked walls, and loosened stones from buildings. At Manhattan, a 0.6-meter wave was seen moving south to north on the Kansas River (USGS, n.d.). 10

12 Figure 4-3. Micro-earthquakes (*) and faults (/) in Kansas (Burchett, Luza, Van Eck, & Wilson, 1983) 3.4. Soil Survey Mapping The soil survey was conducted on Douglas County, which contained required information to manage farms, ranches, and woodlands and to select sites for roads, ponds, building, and other structures to find out the suitability of tracts of land for farming, industry, and recreation as well. The survey distributed the soil in Douglas County into five associations (Deckey, Zimmerman, Plinsky, & Davis, 1977): 11

13 Martin-Sogn-Vinland Association, which make up about 48 percent of the County and includes Martin soil about 35 percent, Sogn soil 18 percent, Vinland soil 14 percent, the remaining is minor soils, as shown in Figure 4. Figure 4-4. Pattern of Soils in Martin-Sogn-Vinland Association in Douglas County, KS (Deckey, Zimmerman, Plinsky, & Davis, 1977) Wabash-Kennebec-Reading Association, which makes up about 12 percent of the County. Pawnee-Woodson-Morrill Association makes up about 9 percent of the County. Sibleyville-Martin-Woodson Association makes up 24 percent of the County. Eudora-Kimo Association makes up 7 percent of the County. 12

14 For dwelling and small commercial buildings, the survey recommend to build structures with a foundation loads have a foundation load not more than three stories high on undisturbed soil. For such structures, soil should be sufficiently stable that neither cracking (or subsidence from settling) nor shear failure of the foundation occur. Soil wetness and depth to a seasonal high water table indicate potential difficulty in providing accurate drainage for basements and gardens (Deckey, Zimmerman, Plinsky, & Davis, 1977) Sub-surface Conditions Subsurface exploration and sampling at the boring locations are indicated on Appendix B Stratification boundaries on the boring log in the data sheet represent the approximate location of changes in material types. The transition between materials may be gradual or abrupt horizontally and vertically in-situ. Based on the results of the boreholes, subsurface conditions of the project site can be generalized, as shown in the Table 2. After fourth stratum the hard layer of soil was encountered. Therefore, bottom of boring at 26.7 feet refused. Table 4-2 Subsurface Conditions Stratum Thickness of Stratum Material Description Moisture Density (feet) Surficial 0.6 Asphalt Pavement N/A N/A 1 st Stratum 2.4 Dark brown and gray clay Very moist Stiff 2 nd Stratum 13.5 Brown clay Moist, less moist with depth Stiff 3 rd Stratum 8.2 Brown clay Slightly moist Stiff 4 th Stratum 2 Light brown clayey silt Dry Firm 13

15 5. Field Exploration 4.1 Bore Hole Preparation KDOT s geotechnical engineering crew demarked the investigation site. KU is going to construct a new Integrated Science buildings and landscaping in the area. The KDOT crew prepared five holes by demarking almost in the straight line. The Test location and demarcations are shown Figure 5.1. Hole 1 Hole Hole 3 Hole 2 Figure 5-1: Test Site Location and Demarcation KDOT crew used a pavement cutter to remove the top of the paved parking lot at site. The cutter size was 10 inches diameter. The borehole prepared after removing the surface paved part is shown in Figure

16 Figure 5-2: Drill Hole Preparation by Removing Top Paved Part 4.2 Drilling and Sampling KDOT crew used hollow flying augur and solid flying augur depending upon the necessities of the test on the particular borehole that were previously planned. Table 5.1 demonstrates the types of test or sampling performed in each boreholes and method of digging of holes. Table 5-1 Location of Boreholes, Types of Digging and Activities Performed Location Borehole Method Activities performed Borehole 1 Hollow flying augur Shelby tube sampling SPT test Vane shear test Disturbed sample collection for lab tests Borehole 2 Solid flying augur Pressure meter test Demonstration of borehole shear test Borehole 3 Bull sampling Bull sampling SPT Borehole 4 Hollow flying augur Shelby tube Borehole 5 Hollow flying augur Shelby tube The undisturbed sampling was carried out by 3.5 inch diameter and 30 inch long Shelby tube. The Shelby tube was penetrated at the required depth as mentioned in Figure 4.3. Altogether 6 15

17 sampling were carried out in Shelby tube. The locations (depth and area) of the Shelby tubes sampling are given in Figure 5.3 and Figure 5.1. Borehole 1 Borehole 4 Borehole ft ft Shelby tube 1 Shelby tube 2 Shelby tube ft ft Shelby tube 4 Shelby tube 5 Shelby tube 6 Figure 5-3 Location of Shelby Tube Sampling Some photographs regarding the boring and sampling are presented in Appendix C. 4.3 Standard Penetration Test (SPT) Standard Penetration Test was carried out at borehole 1 and borehole 4 by inserting 2 inch diameter split-spoon sampler at the different depth. The location of the SPT tests are shown in Figure

18 Borehole 1 Borehole ft ft SPT SPT ft SPT 3 Figure 5-4 Location of Standard Penetration Test at Different Boreholes The measured SPT N value at SPT 1 (borehole 1) was 11, SPT 2 was 13 and SPT 3 was 11. The measured N values at the SPT test and the corresponding outcomes of the test are presented in Table 4.2. The calculations for the outcomes are presented in Appendix C. Table 5-2 SPT Measured and Corrected N Values and Other Outcomes Location Measured N Value Corrected N60 Value N160 Su (kpa) (Terzaghi) Su (kpa) (Hara) SPT 1 (Borehole1) SPT 2 (Borehole SPT 3 (Borehole The Su is almost constant throughout the soil layer. Also, the measured N values are pretty constant in all measured depth. 17

19 4.4 Vane Shear Test The KDOT crew conducted vane shear test at borehole 1 at the depth of 9 ft by using 2 inch diameter tapered vane shear apparatus due to stiffer nature of the clay soil at site. The torque arm length of the vane shear apparatus was 12 inches and the vane shear constant of The critical (failure state) field data and the results are presented in Table 4.3 Table 5-3 Vane Shear Test Results Conditions Failure State applied force (lbf) Undrained shear strength (kpa) Soil Sensitivity Undisturbed Remolded Insensitive The detail calculation of the test results are given in Appendix C and corresponding photographs to vane shear test are given in Appendix C. 4.5 Pressure Meter Test Pressure meter test was carried out at borehole 2 at the depth of 8.0 feet based on ASTM A borehole was drilled with solid continuous auger having 3 inches. The diameter of the pressuremeter probe was 66 mm (2.6 inches). KDOT engineers carried out the calibration of the pressurementer at KDOT lab. Based on the provided data, the calibration curves are presented in Figure

20 Corrected pressure (bar) volume (cm 3 ) Group 2: Final Project Work - Report Volume calibration curve Pressure calibration curve pressure (bar) Figure 5-5 Volume and Pressure Calibration of Pressuremeter Based on the corrected pressuremeter data, the corrected pressuremeter curve is plotted in Figure Corrected volume (cm3) Figure 5-6 Corrected Pressuremeter Curve Showing Elastic Range and Plastic Range 19

21 Group B interpreted the following results from this test: Table 5-4 Result from Pressuremeter Test Name of Test Lateral Earth Pressure Coff. at Rest (K0) Pressuremeter Elastic Modulus (EPMT) kpa Udrained shear strength (Su) kpa Preconsoilidation Stress (σ p) kpa Pressuremeter The more photographs about the pressuremeter test are presented in Appendix D. 4.6 Direct Push Bull Sampling Sampling was carried out by direct push bull sampling and analyzed by inspection. A field log sheet was filled by inspecting the data for classification and characterization of soil. The log sheet obtained from the bull sampling is presented in Appendix C and the photographs related to the bull sampling is given in Appendix D. 20

22 % passing Group 2: Final Project Work - Report 6. Laboratory Testing 5.1 Specific Gravity Determination Group two tested the specific gravity of the sample following by ASTM D We took this sample from Shelby tube. The sample contains all particles less than sieve size 4 and more specifically almost all clay particles. Group two found the specific gravity of 2.69 for the sampled soil. Calculation is presented in Appendix D. 5.2 Grain Size Distribution of Soil Group 2 conducted the standard test for particle size analysis of fine soil based on D From this laboratory test, we found 6.3% of particle retained on sieve size 200 ( <15%). The particle size distribution graph is in Figure 5.1. We found that coefficient of uniformity (Cu) and coefficient of curvature (Cc) are 10 and 0.63 respectively % 80.0% 60.0% 40.0% 20.0% 0.0% Diamter in mm Figure 6-1 Gradation Curve of the Sampled Soil 21

23 5.3 Atterberg Limit Determination We determined the plastic limit and liquid limit based on D The sampled soil have the plastic limit of 24 and the liquid limit of 54. The plasticity index is 30. We found that the soil fall above A-Line in the plasticity chart. And the soil is considered to be CH soil from USCS classification. The laboratory data sheet for the Atterberg limit calculation are presented in Appnendix D. 5.4 Consolidation of Sample Group two performed the 1-D Consolidation Test based on ASTM D at civil engineering lab at KU. This sample was taken from the top part of the Selby tube no 2. The initial void rato of the sample was The overconsolidation (OCR) of the sample was 3.3. The coefficient of consolidation was found as cm 2 /min from Taylor s Square Root Method. Also, we calculated recompression index (Cr) of and compression index (Cc) of The results obtained from 1-D consolidation test are given in Table 5.1: Table 6-1 Results from 1-D Consolidation Test Preconsolidation stress (σp ) D (MPa) Cv by Casagrande s Method Cv by Taylor s Square root method K by Casagrande's kpa MPa cm 2 /min cm 2 /min cm/min x 10-8 Group 2 select the Casagrande s Method to calculate the permeability since Cv of Casagrande s method was lower as compared to Taylor s method. The applied pressure versus void ratio curve, Taylor s square root method and Casagrande s log t method are presented in Figure 5.2, Figure 5.3 and Figure 5.4 respectively. 22

24 Dial reading (in) Void ratio, e Group 2: Final Project Work - Report Pressure, p (kpa) Figure 6-2 Void Ratio versus Pressure Curve (Log Scale) t Square root time Figure 6-3 Taylor`s root time method 23

25 Dial Reading (in) Group 2: Final Project Work - Report t 90 Time, (min) Figure 6-4 Casagrande's log t Method 5.5 Unconfined Compression Test This unconfined compression test was carried out by Zachary Aaron Brady (TA) for undergraduate class and he provided the data of this test. The unconfined compression stress versus the axial strain graph is shown in Figure 6.6. The sample failed at 27.5 psi (189.6 kpa). 24

26 Unconfined compression stress, psi Group 2: Final Project Work - Report Stress strain curve for unconfined compression test Axial Strain, % Figure 6-5 Stress versus Strain Curve of Unconfined Compression Test The undrained shear strength is evaluated as psi (94.8 kpa). 5.6 Consolidated Undrained Test The consolidated undrained triaxial test was carried out from Shelby tube 2 of borehole 4. The sample was extracted by vertical extractor at geotechnical laboratory at KU. Then the sample was cut in average of 2.8 inches diameter and almost 5.8 inches height. The exact dimensions of the sample before placing the triaxial set were 7.2cm (2.836 inches) diameter and cm (5.876 inches) height. The field unit weight of the sample was 19.5 kn/m 3. The sample was left for saturation under cell pressure of 448 kpa (65 psi), the inlet back pressure of 427 kpa (62 psi) and outlet pressure of 414 kpa (60 psi). After saturation, we allowed the sample for consolidation for 48 hours with cell pressure of 522 kpa (75.7 psi) and back pressure of 425 kpa (61.7 psi). After 48 hours of consolidation, the sample was assumed to be consolidated perfectly. Then the sample was sheared. The deviator stress versus strain curve, normal stress versus strain curve and Mohr Column failure envelope are presented in Figure

27 Deviator stress, (psi) Group 2: Final Project Work - Report The sample was considered to be failure at 10% strain and the corresponding deviator stress is 292 kpa (42.4 psi). The results at failure (10% strain) are presented in Table 5.2 Table 6-2 Results from CU Test Group No Deviator pressure Confining Pressure Pore Water Pressure Effective confining pressure Effective Normal Pressure kpa kpa kpa kpa kpa Group Group Axial strain, (%) Figure 6-6 Deviator Stress versus Strain Curve of CU Test 26

28 Deviator stress, (psi) Total and Effective normal stress, (psi) Group 2: Final Project Work - Report Total stress Effective stress Axial strain, % Figure 6-7 Normal Stress versus Axial Strain Curve Group 2 - Total Stress Mohr Circle Group 2 - Effective Stress Mohr Circle Group 1 - Total Stress Mohr Circle Group 1 - Effective Stress Mohr Circle Total Stress Failure Envelope Effective Stress Failure Envelope Stress, (psi) Figure 6-8 Mohr Column Failure Envelope 27

29 7. Foundation Recommendations In order to meet the performance requirement of superstructures, it was recommended that the superstructures should be constructed on a sufficient foundation. Shallow foundations and pile foundations were considered and compared. Based on the load of superstructure and the soil properties provided from the above geotechnical investigation, a piled foundation is recommended to support superstructures. The detailed information is provided in Table Foundation Design Recommendation Table 7-1Recommended pile foundation Description Structures Foundation types The vertical bearing capacity of the single pile Total estimated settlement Value Two-storey building as an extension of Burge Union Piled foundation 2319 kn 7.5 mm Note: 1. a 30-kPa design load for two-storey building was assumed and a 5-m center to center spacing of columns in horizontal directions was assumed as well. A 750-kN load was transferred to the top of the single pile from the column when the single pile supported the column. In the calculation of the vertical bearing capacity of the single pile and the settlement, there were five soil layers along the length of the pile. These soil layers were determined according to the visual observation. The corresponding soil properties were measured from in-situ tests and lab tests. A 15-m long pile with the diameter of 1 m was used to support one column. Since the pile toe is in the firm clay, the pile is considered to be end-bearing pile. In addition, the short term is the control condition because the pile penetrated into the clay layers. The vertical bearing capacity of the single pile uses α method to consider the short term bearing capacity. The factor of safety for bearing capacity was set to be 3. The piles are cast in- 28

30 situ concrete piles. Since the superstructure is two-storey building, the bearing capacity under the lateral loading was not concerned. The calculation of the settlement of the pile used Randolph and Wroth (1978) s method. The considerations of soil parameters and the detailed calculation of the vertical bearing capacity of a single pile is shown in Appendix F. The consideration of soil parameters and the detailed calculation of the settlement can be seen in Appendix G. Figure 7-1 Soil profile for the design of the piled foundation The vertical bearing capacity of the single pile and its settlement are up to the uncertain conditions, such as the subsurface profile, the structural conditions, and the quality of construction operations. Piled foundations under these variable conditions could experience less vertical bearing capacity and greater total and differential settlement than estimated and may not be predictable. The field monitoring is recommended to guarantee the predicted results are sufficiently accurate. 29

31 6.2 Foundation Construction Considerations The cast in-situ concrete piles will be installed into the soil. The soil properties may change due to the disturbance resulting from boring. The disturbed soil may reduce the vertical bearing capacity of the single pile and increase the settlement. In addition, the pile integrity tests are suggested to check the quality of installed piles. A pile cap has to be cast in situ on the top of the pile to connect a column. 8. Conclusions and comments From the field test, the undrained shear strength of the foundation soil was very high. The undrained shear strength were an average of 72 kpa from SPT test, 92.4 kpa from Vane shear test (undisturbed) and 71 kpa from pressruemeter test. This result was supported by the laboratory test as the unconfined compressive gives the undrained shear strength of 94.8 kpa. So, the foundation is strong enough to support probable foundation. Also, from consolidation test, it was found that the filed was over consolidated. Also, the permeability of the soil is very small. The piled foundation is recommended to support the two-storey building. The calculated vertical bearing capacity and the settlement of the single pile were 2391 kn and 7.5 mm, respectively. The calculated vertical bearing capacity of the single pile may reduce and the settlement of the single pile may increase due to variation of the subsurface profile, the structural conditions, and the quality of construction operations. 30

32 9. References Burchett, R. R., Luza, K. V., Van Eck, O. J., & Wilson, F. W. (1983). Seismicity and tectonic relationships of the Nemaha Uplift and Midcontinent geophysical anomaly. Final project summary. Lincoln,Norman,Iowa city, Lawrence: Nebraska University ; Oklahoma Geological Survey; Iowa Geological Survey; Kansas Geological Survey. Data, U. C. (n.d.). Climate Lawrence - Kansas. Retrieved 05 09, 2015, from Deckey, H. P., Zimmerman, J. L., Plinsky, R. O., & Davis, R. D. (1977). Soil Survey of Douglas County. Kansas. pickatrail. (n.d.). Lawrence East, Kansas 7.5 Minute Topo Map. Retrieved 05 09, 2015, from Places, S. B. (2015, 05 08). Climate in Lawrence, Kansas. Retrieved from USGS. (n.d.). Kansas Earthquake Information. Retrieved 05 09, 2015, from earthquake.usgs.gov/: 31

33 Appendix A: Filed exploration New Construction Figure 9-1. KU Central District Plan (dcm.ku.edu)

34 Test Location 34

35 Figure 9-2. Site Location Plan Boring 1 Boring 2 Boring 3 Boring 4 Boring 5 Figure 9-3. Borings Location plan 35

36 Test Location Figure 9-4. Topography map of Test Location (3) 36

37 10. Appendix B: Boring log Sheet Figure Subsurface Exploration and Sampling Sheet ( 19 feet depth) 37

38 Figure Subsurface Exploration and Sampling Sheet (>19 feet depth) 38

39 11. Appendix C: Field Test Data Sheet 39

40 40 Group 2: Final Project Work - Report

41 41 Group 2: Final Project Work - Report

42 42 Group 2: Final Project Work - Report

43 12. Appendix D: Lab Test Data Sheet Appendix D: Field Moisture Content Determination Nos of Sample Container Name Empty Wt. of Container Container + Wet Weight of Soil Container + Dry Weight of Soil Moisture Content of Smaple L3AJ Average MC 24.3% Appendix D: Specific Gravity Test Data Wt. of empty flask wt. of flask+water wt. of flask+water+soil Mass of dry soil Temperature gm gm gm Degree C Appendix D: Liquid Limit Determination No. of blow Can Identification Empty wt. of Can Can + Moist Soil Wt. Can+ Dry soil Wt. MC Hall % % EAGS % % M % I# % CBM % DM % % mv % So, from graph, liquid limit is % 51.5% 54.0% 53.0% 58.2% 43

44 Appendix D: Plastic Limit Determination Can Identification Empty wt. of Can Can + Moist Soil Wt. Can+ Dry soil Wt. MC Average MC E % FR Appendix D Gradation by Hydrometer Analysis General Data Tested By: Group 2 Moisture content Date: 4/27/2015 M of Container 0 gm Mass of air dry, M Mass of Soil + Container - Wet 50 Specific Gravity, Gs 2.69 Mass of Soil + Container - Dry 0 Hydrometer: 152H Dry mass of Soil 0 Meniscus correction, Fm 0.5 w 0.00% mass of soilds, Ms 50 Dry mass of soil 50 g α correction: gm Time, T(min) Zero Correction Hydrometer Reading Corrected Reading % Finer K Diameter (mm) 93.7% % % % % % % % % % % % % %

45 Appendix D: Consolidation Test Data Sheet and Calculation time (min) Accumulative time (min) time root Loading (kg) kg Pressure (kpa) dial reading dial reading (in)

46 Appendix D: Consolidation Test Calculation 46

47 47 Group 2: Final Project Work - Report

48 48 Group 2: Final Project Work - Report

49 49 Group 2: Final Project Work - Report

50 13. Appendix F: The Calculation of Vertical Bearing Capacity of a Single Pile The short term is the control condition for vertical bearing capacity of the single pile in this project. Therefore the undrained condition (i.e., α method is used for friction resistance) was used to calculate the vertical bearing capacity of the single pile. The undrained shear strengths of soils were calculated from the results of SPT, the vane shear tests, the unconfined compression tests, and the pressure meter tests. The undrained shear strengths of soils from the results of SPT were selected to yield a conservative design. The properties of soils for the calculation of vertical bearing capacity of the single pile are summarized in Table F.1. Table F.1 the properties of soils Layer Soil Top (ft) Bottom (ft) Thickness (m) Undrained shear strength (kpa) 1 Dark brown and gray clay Brownish gray clay Dark reddish brown clay Brown clay, slightly moist Light brown clayey silt The values of α were calculated based on API method. The equations of calculation were given in the following: (Equation F.1)

51 The α values, friction resistance, and friction bearing load are summarized in Table F.2. Table F.2 the calculated results for side bearing load Layer Soil α Friction resistance, fs (kpa) Frinction bearing load (kn) 1 Dark brown and gray clay Brownish gray clay Dark reddish brown clay Brown clay, slightly moist Light brown clayey silt The toe resistance was calculated based on the following Equation (F.2): (Equation F.2) The bearing capacity of the single pile is the sum of friction bearing capacity and toe bearing capacity. The allowable load applied on the top of pile is Q Q s Q t (Equation F.3) Q Q allowable (Equation F.4) FS Calculation example: 1. Friction bearing capacity (α method): For Layer 1, the soil is Dark brown and gray clay. Its undrained shear strength is 66 kpa, which is less than 75 kpa but greater than 25 kpa. s 25/ / u f s kpa s u Q s f s A s kN 48

52 2. Toe bearing capacity * q N s kpa t c u 3.14 Q t qt At kn 4 3. The vertical bearing capacity of a single pile Q Q s Q kn t 4. The allowable load applied on the top of pile Q Q allowable FS kn>750 kn 3 49

53 14. Appendix G: The Calculation of settlement of a Single Pile The calculation of settlement of a single pile used Randolph and Wroth (1978) s method. PI (Equation G.1) E d Where P is the axial load at the top of the pile, I is the influence factor, modulus at the toe, and d is the diameter of the pile. D E D is the soil The axial load transfers to the top of pile P 750 kn, and the diameter of pile d 1 m. The moduli of soils for different layers were estimated using the results from triaxial tests, onedimensional consolidation tests, vane shear tests, and pressure meter tests. The comparison of these results was conducted to determine the design value used in the calculation. The moduli of clays at the pile toe and below the pile toe were 10 MPa (i.e., E D 10 MPa, E b 10 MPa). The average modulus of clays was also 10 MPa (i.e., Eavg 10 MPa). Poisson s ratio of clays were 0.3. In addition, the modulus of the pile was 30 GPa. Calculation example: The pile length, D 15 m d b d E E D b

54 D avg E E D p s E E 3.96 )} ]( 0.25) 0.3) (1 1 (2.5 ln{[0.25 )} 2 ]( 0.25) ) (1 (2.5 ln{[0.25 d D s d D D 0.1 } tanh { } tanh { } tanh { } tanh {1 4 1 d D D D d D D D I s s s d E PI D mm