15 pile-supported highway embankmentweb.mst.edu/~norbert/ge5471/assignments/assign 1 - flac...

Pile-Supported Highway Embankment 15 - 1

15 Pile-Supported Highway Embankment

15.1 Problem Statement

End-bearing piles can be used to support highway embankments constructed over soft foundationmaterials. This method of support can reduce the potential for excessive deformations and failureduring the undrained stage of construction, when excess pore pressures are induced in the foundationmaterials by the embankment loading.

This example presents a FLAC analysis of the initial (undrained) construction stage for a highwayembankment built over soft, saturated foundation clay and muck, using timber piles to supportthe embankment.* The piles extend through the soft materials and into underlying silty sands.The embankment includes foamed concrete engineered fill as part of the embankment materials.The lightweight foamed concrete is placed in lifts of approximately 0.6 m thickness. The firstlift is placed over a wire mesh directly in contact with the top of the timber piles. Earth fill andpavement material are placed as cover over the foamed concrete. The analysis also includes atraffic surcharge of 11,500 Pa (240 psf). Figure 15.1 shows a section view of the embankment andfoundation materials. The groundwater surface is at the top of the foundation materials.

Figure 15.1 Half-section view of foamed concrete embankment on timberpiles

* This analysis is based on information provided by K. J. Kim of the North Carolina Department ofTransportation on the design of a foamed concrete embankment supported on timber piles for theU.S. 64 widening project in Tyrrell County, North Carolina.

FLAC Version 6.0

15 - 2 Example Applications

The properties assumed for the foundation and embankment materials are listed in Tables 15.1and 15.2. Note that both saturated and dry densities are shown for the foundation materials. Theembankment materials are assumed to remain dry. The FLAC simulation is an undrained analysisusing the groundwater configuration mode. Consequently, the drained material bulk modulus andstrength properties and the dry mass densities are input for this calculation mode, because the effectof water is incorporated in the FLAC calculation.

Table 15.1 Properties for foundation soils

muck very soft clay silty sand

Saturated unit weight (N/m3) 11,100 13,560 18,840Porosity (%) 90 80 30Dry density (kg/m3) 231 582 1620Drained Young’s modulus (MPa) 0.3 0.5 15.0Drained Poisson’s ratio 0.49 0.45 0.3Drained bulk modulus (MPa) 5.0 1.67 12.5Shear modulus (MPa) 0.1 0.17 5.77Drained cohesion (Pa) 3500 5000 0Drained friction angle (degrees) 0 0 32Dilation angle (degrees) 0 0 0Horizontal permeability (m/day) 0.003 0.0003 2.4Vertical permeability (m/day) 0.001 0.0001 0.8

Table 15.2 Properties for embankment materials

foamed concrete earth fill

Dry density (kg/m3) 640 1920Porosity (%) 30 30Drained Young’s modulus (MPa) 600.0 10.0Drained Poisson’s ratio 0.15 0.3Drained bulk modulus (MPa) 286.0 8.33Shear modulus (MPa) 261.0 3.85Drained cohesion (Pa) 50,000 2400Drained friction angle (degrees) 0 30Dilation angle (degrees) 0 0Horizontal permeability (m/day) 1.2 1.2Vertical permeability (m/day) 0.4 0.4

Treated timber piles are located on a 2.5 m by 2.5 m rectangular spacing beneath the embankmentmaterials. The length of each pile is 12.8 m (42 ft), and the average pile diameter is 0.3048 m(12 in). The properties of the timber piles are listed in Table 15.3.

FLAC Version 6.0


Table 15.3 Properties for treated timber piles

Elastic modulus (GPa) 10.0End-bearing capacity (KN) 250.0

15.2 Modeling Procedure

This analysis is performed as a parametric study to compare the deformation of an unsupportedembankment to that of a pile-supported embankment. In both cases, we first determine the initialequilibrium state of the saturated foundation soils. Then, for the unsupported case, we add theembankment materials and monitor the vertical displacement along the foundation surface directlybeneath the embankment. For the pile-supported case, we install the timber piles and then add thelayers of embankment materials while monitoring the vertical displacements in the same locationsas those for the unsupported case.

The model is created using FLAC ’s graphical interface, the GIIC. Upon entering the GIIC, thegroundwater flow option, structural elements and factor-of-safety calculation are activated in theModel Options dialog. The Save Project As menu item is then selected from the File menu inorder to set up a project file to save the model state at various stages of the simulation. We click on? in this menu dialog to select a directory in which to save the project file. A record of the FLACcommands used to create this model is saved after the analysis is complete, using the File / ExportRecord menu item. A listing of the record created for this model is given in Section 15.3.

We generate the grid using the Build/Generate/Block tool to create a two block by two block grid. Then,we use the Alter/Shape tool to generate lines defining the excavation slope and the excavation andfoundation material boundaries. The embankment is 3 m high and the pavement half-width is 12 m.The resulting grid is shown in Figure 15.2 and coincides with the half-section shown in Figure 15.1.The grid before alteration is saved as state “P1.SAV,” and after alteration as “P2.SAV.”

FLAC Version 6.0


FLAC (Version 6.00)

LEGEND

30-Jun-08 13:25 step 0 -4.500E+00 <x< 8.550E+01 -6.300E+01 <y< 2.600E+01

Grid plot

0 2E 1

-5.500

-4.500

-3.500

-2.500

-1.500

-0.500

0.500

1.500

(*10^1)

0.500 1.500 2.500 3.500 4.500 5.500 6.500 7.500(*10^1)

JOB TITLE : PILE-SUPPORTED HIGHWAY EMBANKMENT

Itasca Consulting Group, Inc. Minneapolis, Minnesota USA

Figure 15.2 FLAC grid for highway embankment analysis

The different materials and their associated properties are assigned by group names using theMaterial/Assign tool. Three foundation soil groups are created: silty sand, very soft clay and muck.The embankment consists of four lifts of 0.6 m thick foamed concrete and the earth fill layer.The groups defined for the embankment and foundation materials are shown in Figure 15.3. Thegroundwater properties are assigned using the Material/GWProp tool. The model is saved at this stageas “P3.SAV.”

FLAC Version 6.0


Figure 15.3 Groups defined for embankment and foundation materials

After all of the material groups are assigned, the foamed concrete lifts and earth fill groups are“excavated” using the Material/Cut&Fill tool. The initial stress state for the saturated foundation soilsis then calculated. We use the “ININV.FIS” FISH function provided in the FISH library (see“ININV.FIS” in Section 3 in the FISH volume). This function automatically calculates the porepressures and total stresses that are compatible for a model containing a phreatic surface. Thegroundwater density and water bulk modulus are specified before applying this FISH function.We use the Settings/GW tool to set the groundwater density to 1000 kg/m3 and the groundwater bulkmodulus to 10,000 Pa (to speed convergence to steady-state flow). We then use the Utility/FishLib

tool to access the “ININV.FIS” FISH function. We enter the phreatic surface elevation (wth = 0)and the Ko ratios (k0x = 1.0 and k0z = 1.0) in the dialog, and press OK . The FISH function iscalled into FLAC and executed. The pore-pressure distribution and total stress adjustment are thencalculated automatically. We now solve for the new equilibrium state, using the Run/Solve tool andrunning in coupled mechanical-groundwater flow mode. The pore-pressure distribution is shownin Figure 15.4. The model is saved at this state as “P4.SAV.”

FLAC Version 6.0


FLAC (Version 6.00)

LEGEND

20-Jun-08 9:55 step 2113Flow Time 1.8759E+06 -4.500E+00 <x< 8.550E+01 -6.300E+01 <y< 2.600E+01

Pore pressure contours 0.00E+00 5.00E+04 1.00E+05 1.50E+05 2.00E+05 2.50E+05 3.00E+05 3.50E+05

Contour interval= 5.00E+04

-5.500

-4.500

-3.500

-2.500

-1.500

-0.500

0.500

1.500

(*10^1)

0.500 1.500 2.500 3.500 4.500 5.500 6.500 7.500(*10^1)



Figure 15.4 Initial pore-pressure distribution in foundation soils

The embankment construction is analyzed assuming undrained conditions. This is accomplishedby setting the groundwater flow calculation mode off, and increasing the water bulk modulus toapproximate a nearly incompressible fluid. We increase the water bulk modulus to 0.2 GPa andset flow off using the Settings/GW tool. Also, because we anticipate large deformations during theconstruction, we perform this stage in large-strain mode and set this option on in the Settings/Mech

tool.

The unsupported embankment construction is simulated by adding each embankment-lift groupindividually (via the Material/Cut&Fill tool), and then solving for the equilibrium state with this liftin place. As each group is added, the saturation values of the gridpoints in the group are fixedat zero (using the In Situ/Initial and In Situ/Fix tools) to simulate the unsaturated condition of theembankment materials. Figure 15.5 shows the Material/Cut&Fill tool with the “foamed concrete1” liftadded (filled). (We note that if the Show Excavations? box is checked, then the excavated groups areshown grayed-out in this tool.) These steps are repeated for each of the three remaining foamedconcrete lifts and the earth-fill lift. Finally, the traffic surcharge is applied along the top of theembankment, using the In Situ/Apply tool. Each of the unsupported construction stages is saved as aseparate save state in “P5.SAV” through “P10.SAV.”

FLAC Version 6.0


Figure 15.5 Addition of first embankment lift “foamed concrete1”

Vertical displacement histories are recorded at four locations along the base of the embankment, at(x = 0, y = 0), (x = 5, y = 0), (x = 11, y = 0) and (x = 16, y = 0). The displacements are monitoredthroughout the embankment construction; the results are shown in Figure 15.6. The extent of thedisplacements induced by the unsupported construction is shown in Figure 15.7. The maximumvertical displacement beneath the embankment is approximately 0.6 m (2 ft).

The displacements are associated with excess pore pressures that develop in the muck and verysoft clay. This is evident from the pore-pressure histories recorded along the centerline of theembankment at y = 0 and y = −6 (in the muck), and at y = −10 (in the very soft clay). The plotsof pore-pressure histories are given in Figure 15.8.

A factor-of-safety calculation is performed at this stage by selecting the Run/SolveFoS tool. The safetyfactor for the unsupported embankment is calculated to be 1.06. Figure 15.9 shows the failuresurface that develops if cohesion and friction of the embankment and foundation materials arereduced by this factor.

FLAC Version 6.0


FLAC (Version 6.00)

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20-Jun-08 9:55 step 74960Flow Time 1.8759E+06 HISTORY PLOT Y-axis : 1 Y displacement( 1, 41)

2 Y displacement( 6, 41)



X-axis :Number of steps

10 20 30 40 50 60 70

(10 ) 03

-5.000

-4.000

-3.000

-2.000

-1.000

0.000

(10 )-01



Figure 15.6 Vertical displacements along base of embankment for unsup-ported embankment construction

FLAC (Version 6.00)

LEGEND


X-displacement contours 0.00E+00 1.00E-01 2.00E-01 3.00E-01 4.00E-01 5.00E-01 6.00E-01 7.00E-01 8.00E-01

Contour interval= 1.00E-01Displacement vectorsmax vector = 8.534E-01

0 2E 0

-4.000

-3.000

-2.000

-1.000

0.000

1.000

2.000

(*10^1)

0.500 1.500 2.500 3.500 4.500 5.500(*10^1)



Figure 15.7 Displacement vectors and x-displacement contours for unsup-ported embankment construction

FLAC Version 6.0


FLAC (Version 6.00)

LEGEND

20-Jun-08 9:55 step 74960Flow Time 1.8759E+06 HISTORY PLOT Y-axis : 5 Grid-point pp ( 1, 40)

8 Grid-point pp ( 1, 30)



10 20 30 40 50 60 70

(10 ) 03

0.200

0.400

0.600

0.800

1.000

1.200

(10 ) 05



Figure 15.8 Pore pressures beneath center of embankment for unsupportedembankment construction

FLAC (Version 6.00)

LEGEND


Factor of Safety 1.06Max. shear strain increment 0.00E+00 5.00E-02 1.00E-01 1.50E-01 2.00E-01 2.50E-01 3.00E-01 3.50E-01 4.00E-01

Contour interval= 5.00E-02Velocity vectorsmax vector = 1.257E-06

0 2E -6-4.000

-3.000

-2.000

-1.000

0.000

1.000

2.000

(*10^1)

0.500 1.500 2.500 3.500 4.500 5.500(*10^1)



Figure 15.9 Factor of safety and failure surface plot for unsupported embank-ment

FLAC Version 6.0


The pile-supported embankment construction is simulated by first installing pile elements in theFLAC model. The model state at “P4.SAV” (the initial equilibrium state) is restored, and sevenpiles of 12.8 m length are positioned at a 2.5 m spacing within the foundation soils. Before thepiles are placed in the model, the first foamed concrete lift is added. This is done so that the top ofthe piles can be connected to the embankment materials. Then, the piles are positioned as shownin Figure 15.10.

In order to represent the three-dimensional effect of the 2.5 m pile spacing, we scale the pileproperties by dividing by the pile spacing. This is done automatically by specifying the spacingproperty when assigning pile properties. In this analysis, only the elastic modulus and the end-bearing capacity are scaled to account for the spacing. Note that we neglect the weight of the piles;the pile density would also be scaled if this weight is included. (See Section 1.9.4 in StructuralElements for additional information on scaling properties to simulate the three-dimensional effect.)

The properties of the pile coupling springs are selected to simulate an end-bearing capacity and zeroskin friction. The cohesive strengths of the shear coupling springs at the top and bottom elementsof each pile are set to 2.5 MN/m, while all other shear and normal coupling-spring strength valuesare set to zero. The value for cohesive strength is derived from a simulation of axially loadedpiles at 2.5 m spacing to produce an end-bearing ultimate capacity of 250 KN in the silty-sandfoundation material. The value for coupling-spring shear stiffness is selected at approximately tentimes the equivalent stiffness of the stiffest neighboring zone. By doing this, the deformability atthe pile/soil interface will have minimal influence on both the compliance of the total model andthe calculational speed (see Section 5.4.1 in Theory and Background). The properties used forthe pile elements in this model are summarized in Table 15.4. The model is saved at this stage as‘P11.SAV.”

Figure 15.10 Location of piles in FLAC model

FLAC Version 6.0


Table 15.4 Properties for pile elements

middle segments top & bottom segments

Elastic modulus (GPa) 10.0 10.0Radius (m) 0.1524 0.1524Perimeter (m) 0.976 0.976Spacing (m) 2.5 2.5Shear coupling spring stiffness (GN/m/m) 0.0 1.0Shear coupling spring cohesion (MN/m) 0.0 2.5Shear coupling spring friction (degrees) 0.0 0.0Normal coupling spring stiffness (GN/m/m) 0.0 0.0Normal coupling spring cohesion (N/m) 0.0 0.0Normal coupling spring friction (degrees) 0.0 0.0

The embankment construction steps are now performed following the same sequence as for theunsupported case. Each of the pile-supported stages is saved as a separate save state in “P12.SAV”through “P17.SAV.”

The vertical displacements are monitored as before; the histories are shown in Figure 15.11. Themaximum vertical displacement beneath the embankment is now approximately 0.03 m (1 in).

Also, we note that for this case there is an insignificant change in pore pressures in the muck andvery soft clay, as seen in Figure 15.12.

FLAC Version 6.0


FLAC (Version 6.00)

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20-Jun-08 9:55 step 66128Flow Time 1.8759E+06 HISTORY PLOT Y-axis : 1 Y displacement( 1, 41)





10 20 30 40 50 60

(10 ) 03

-5.000

-4.000

-3.000

-2.000

-1.000

0.000

1.000

(10 )-01



Figure 15.11 Vertical displacements along base of the embankment for pile-supported embankment construction

FLAC (Version 6.00)

LEGEND

20-Jun-08 9:55 step 66128Flow Time 1.8759E+06 HISTORY PLOT Y-axis : 5 Grid-point pp ( 1, 40)




10 20 30 40 50 60

(10 ) 03

0.200

0.400

0.600

0.800

1.000

(10 ) 05



Figure 15.12 Pore pressures beneath center of embankment for pile-supportedembankment construction

FLAC Version 6.0


We are also interested in the axial loading that develops in the piles. When the spacing property isassigned, the axial force values that are printed and plotted output are the actual values (i.e., theyaccount for the pile spacing). We plot the actual axial forces in the piles in Figure 15.13. (The 21 pilenumbers shown in the plot legend correspond to the top, middle and bottom pile segments, whichare assigned different material property numbers.) The maximum pile loading is approximately210 KN.

A factor-of-safety calculation is also performed at this stage. The calculated factor is 1.46, and thefailure surface is shown by the plot in Figure 15.14. Note that the critical failure surface for thesupported embankment is now at the toe of the earthfill berm. The safety factor for the foundationmaterial beneath the embankment is greater than 1.46, as a result of the support provided by thepiles.

Finally, we note that this project can be re-created by importing the data file “PEMBANK.DAT”listed in Section 15.3, using the File / Import Record menu item. After the record is imported tothe GIIC, each save state can be created by first clicking on that state in the Record pane, and thenclicking on the restore state button at the top of the pane. The commands associated with that statewill then be called into FLAC. Note that the Project Tree Record format must be enabled (from theModel Options dialog) to import this record.

Figure 15.13 Actual loads in piles for pile-supported embankment construction

FLAC Version 6.0


FLAC (Version 6.00)

LEGEND


Factor of Safety 1.46Max. shear strain increment 0.00E+00 2.00E-01 4.00E-01 6.00E-01 8.00E-01 1.00E+00 1.20E+00

Contour interval= 2.00E-01Velocity vectorsmax vector = 1.964E-05

0 5E -5

-4.000

-3.000

-2.000

-1.000

0.000

1.000

2.000

(*10^1)

0.500 1.500 2.500 3.500 4.500 5.500(*10^1)



Figure 15.14 Factor of safety and failure surface plot for supported embank-ment

FLAC Version 6.0


15.3 Data File “‘PEMBANK.DAT”

Project Record Tree export;Title:Piled Embankment

;... State: p1.sav ....config gwflowgrid 60,45gen 0.0,-40.0 0.0,-15.0 30.0,-15.0 30.0,-40.0 ratio 1.0,0.9 i 1 31 j 1 16gen 0.0,-15.0 0.0,3.0 30.0,3.0 30.0,-15.0 i 1 31 j 16 46gen 30.0,-40.0 30.0,-15.0 80.0,-15.0 80.0,-40.0 ratio 1.02,0.9 &i 31 61 j 1 16

gen 30.0,-15.0 30.0,3.0 80.0,3.0 80.0,-15.0 ratio 1.02,1.0 i 31 61 j 16 46model elastic i 1 60 j 1 45save p1.sav

;... State: p2.sav ....gen line 11.75,3.0 20.75,0.0gen line 0.0,-9.0 20.0,-5.0gen line 0.0,-12.0 20.0,-10.5mark i 21 61 j 41mark i 20 61 j 32mark i 20 61 j 23mark i 1 20 j 41model null i 21 j 41 45model null i 20 j 42 45model null i 19 j 42 45model null i 18 j 43 45model null i 17 j 43 45model null i 16 j 44 45model null i 15 j 44 45model null i 14 j 45model null region 45 43gen line 0.0,2.5 11.0,2.5ini x 12.543801 y 2.0714378 i 13 j 44ini x 13.681461 y 1.5236754 i 14 j 43ini x 15.619698 y 0.84950686 i 16 j 42ini x 14.187088 y 1.3551335 i 15 j 43ini x 16.336002 y 0.63882875 i 17 j 42save p2.sav

;... State: p3.sav ....group ’silty sand’ region 55 5model mohr group ’silty sand’prop density=1620.0 bulk=1.2499999E7 shear=5770000.0 cohesion=0.0 &friction=32.0 dilation=0.0 tension=0.0 group ’silty sand’

FLAC Version 6.0


group ’very soft clay’ region 59 29model mohr group ’very soft clay’prop density=582.0 bulk=1669999.9 shear=172000.0 cohesion=5000.0 &friction=0.0 dilation=0.0 tension=0.0 group ’very soft clay’

group ’muck’ region 58 36model mohr group ’muck’prop density=231.0 bulk=5.0002132E6 shear=100066.7 cohesion=3500.0 &friction=0.0 dilation=0.0 tension=0.0 group ’muck’

group ’foamed concrete1’ i 1 17 j 41model mohr group ’foamed concrete1’prop density=640.0 bulk=2.85999968E8 shear=2.61E8 cohesion=500000.0 &friction=0.0 dilation=0.0 tension=0.0 group ’foamed concrete1’




group ’earth fill’ i 20 j 41model mohr group ’earth fill’prop density=1920.0 bulk=8330000.0 shear=3850000.0 cohesion=2400.0 &friction=30.0 dilation=0.0 tension=0.0 group ’earth fill’





group ’earth fill’ i 16 j 42model mohr group ’earth fill’

FLAC Version 6.0


prop density=1920.0 bulk=8330000.0 shear=3850000.0 cohesion=2400.0 &friction=30.0 dilation=0.0 tension=0.0 group ’earth fill’


group ’earth fill’ i 14 15 j 43model mohr group ’earth fill’prop density=1920.0 bulk=8330000.0 shear=3850000.0 cohesion=2400.0 &friction=30.0 dilation=0.0 tension=0.0 group ’earth fill’

group ’earth fill’ notnull i 13 14 j 44 45model mohr group ’earth fill’prop density=1920.0 bulk=8330000.0 shear=3850000.0 cohesion=2400.0 &friction=30.0 dilation=0.0 tension=0.0 group ’earth fill’

group ’earth fill’ i 1 12 j 45model mohr group ’earth fill’prop density=1920.0 bulk=8330000.0 shear=3850000.0 cohesion=2400.0 &friction=30.0 dilation=0.0 tension=0.0 group ’earth fill’

prop por=0.3 k11=2.83E-9 k22=9.44E-10 group ’foamed concrete1’prop por=0.3 k11=2.83E-9 k22=9.44E-10 group ’foamed concrete2’prop por=0.3 k11=2.83E-9 k22=9.44E-10 group ’foamed concrete3’prop por=0.3 k11=2.83E-9 k22=9.44E-10 group ’foamed concrete4’prop por=0.3 k11=2.83E-9 k22=9.44E-10 group ’earth fill’prop por=0.3 k11=2.83E-9 k22=9.44E-10 group ’silty sand’prop por=0.8 k11=3.54E-13 k22=1.17E-13 group ’very soft clay’prop por=0.9 k11=3.53E-12 k22=1.18E-12 group ’muck’save p3.sav

;... State: p4.sav ....model null group ’earth fill’model null group ’foamed concrete4’model null group ’foamed concrete3’model null group ’foamed concrete2’model null group ’foamed concrete1’fix x y i 1 61 j 1fix x i 61 j 1 41fix x i 1 j 1 41set gravity=9.81water bulk 2e4water density=1000.0set echo offcall Ininv.fisset wth=0.0 k0x=0.5 k0z=0.5ininvhistory 999 unbalancedsolve

FLAC Version 6.0


save p4.sav

;*** Branch: Unsupported ****

;... State: p5.sav ....model mohr group ’foamed concrete1’prop density=640.0 bulk=2.85999936E8 shear=2.61E8 cohesion=500000.0 &friction=0.0 dilation=0.0 tension=0.0 group ’foamed concrete1’

initial saturation 0.0 i 1 18 j 41 42fix saturation i 1 18 j 41 42set flow=offwater bulk=2.0E8set =largefix x i 1 j 41 42history 1 ydisp i=1, j=41history 2 ydisp i=6, j=41history 3 ydisp i=12, j=41history 4 ydisp i=17, j=41history 5 gpp i=1, j=40history 8 gpp i=1, j=30history 9 gpp i=1, j=23history 10 gpp i=1, j=14initial xdis 0.0 ydis 0.0solvesave p5.sav


fix x i 1 j 42 43fix saturation i 1 16 j 42 43initial saturation 0.0 i 1 16 j 42 43solvesave p6.sav



FLAC Version 6.0




;... State: p9.sav ....model mohr group ’earth fill’prop density=1920.0 bulk=8330000.0 shear=3850000.0 cohesion=2400.0 &friction=30.0 dilation=0.0 tension=0.0 group ’earth fill’


;... State: p10.sav ....apply pressure 11500.0 from 1,46 to 12,46solvesave p10.sav

;... State: FoSmode.fsv ....;FoS save state:solve fos file FoSmode.fsv

;*** Branch: Pile-supported ****restore p4.sav


struct node 1 1.251,0.01struct node 2 1.25,-12.8struct node 3 3.751,0.01struct node 4 3.75,-12.8struct node 5 6.251,0.01struct node 6 6.25,-12.8struct node 7 8.751,0.01struct node 8 8.75,-12.8struct node 9 11.251,0.01struct node 10 11.25,-12.8

FLAC Version 6.0


struct node 11 13.751,0.01struct node 12 13.75,-12.8struct node 13 16.251,0.01struct node 14 16.25,-12.8struct pile begin node 1 end node 2 seg 10 prop 3001struct pile begin node 3 end node 4 seg 10 prop 3001struct pile begin node 5 end node 6 seg 10 prop 3001struct pile begin node 7 end node 8 seg 10 prop 3001struct pile begin node 9 end node 10 seg 10 prop 3001struct pile begin node 11 end node 12 seg 10 prop 3001struct pile begin node 13 end node 14 seg 10 prop 3001struct prop 1001struct prop 2001struct prop 3001struct prop 3001 e 1E10 radius 0.1524 perimeter 0.976 cs ncoh 0 cs nfric 0 &cs nstiff 0 cs scoh 0.0 cs sstiff 0.0 cs sfric 0 spacing 2.5

struct prop 3002 e 1E10 radius 0.1524 cs scoh 2500000.0 cs sstiff 1e9 per &0.976 spacing 2.5

struct prop 3002 cs ncoh 0 cs nstiff 0struct chprop 3002 range 70 70struct chprop 3002 range 60 60struct chprop 3002 range 50 50struct chprop 3002 range 40 40struct chprop 3002 range 30 30struct chprop 3002 range 20 20struct chprop 3002 range 10 10struct chprop 3002 range 61 61struct chprop 3002 range 51 51struct chprop 3002 range 41 41struct chprop 3002 range 31 31struct chprop 3002 range 21 21struct chprop 3002 range 11 11struct chprop 3002 range 1 1water bulk 2e8set flow offfix x i 1 j 40 42save p11.sav

;... State: p12.sav ....history 1 ydisp i=1, j=41history 2 ydisp i=6, j=41history 3 ydisp i=12, j=41history 4 ydisp i=17, j=41history 5 gpp i=1 j=40history 8 gpp i=1 j=30history 9 gpp i=1 j=23

FLAC Version 6.0


history 10 gpp i=1 j=14set largeinitial xdis 0.0 ydis 0.0initial saturation 0.0 i 1 18 j 41 42fix saturation i 1 18 j 41 42solvesave p12.sav


initial saturation 0.0 i 1 16 j 42 43fix saturation i 1 16 j 42 43solvesave p13.sav


fix x i 1 j 43 46initial saturation 0.0 i 1 19 j 42 46fix saturation i 1 19 j 42 46solvesave p14.sav



;... State: p16.sav ....model mohr group ’earth fill’prop density=1920.0 bulk=8330000.0 shear=3850000.0 cohesion=2400.0 &friction=30.0 dilation=0.0 tension=0.0 group ’earth fill’


FLAC Version 6.0


;... State: p17.sav ....apply pressure 11500.0 from 1,46 to 11,46solvesave p17.sav

;... State: FoSmode2.fsv ....;FoS save state:solve fos no restore file FoSmode2.fsv

;*** plot commands ****;plot name: pore pressureplot hold pp fill;plot name: y-disp historiesplot hold history 1 line 2 line 3 line 4 line;plot name: displacementsplot hold xdisp fill displacement;plot name: pp historiesplot hold history 5 line 8 line 9 line;plot name: pile forcesplot hold group struct pile axial fill max 1000000.0;plot name: FoSplot hold fos ssi fill velocity

FLAC Version 6.0

15 pile-supported highway embankmentweb.mst.edu/~norbert/ge5471/assignments/assign 1 - flac...

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