LATERAL ANALYSIS OF PILES USER MANUAL

1www.geocalcs.com/lapLATERAL ANALYSIS OF PILES USER MANUALJames P. Doherty2020james.doherty@uwa.edu.auVersion 2.0

2Table of Contentswww.geocalcs.com/lap . 1Lateral Analysis of Piles User Manual . 1List of Tables . 4List of Figures . 5General information . 7Terms of use . 8Getting started . 9Outline. 9Project . 9Pile . 10Soil . 14GWT . 17Loads . 17Springs . 20Settings . 20Results . 21Modelling . 23Defining geometry . 23Soil profile and initial stress . 24Pile properties . 29Soil Springs . 30Outline. 30Elastic perfectly-plastic (calculated) . 30Elastic perfectly-plastic (user defined) . 33

3Sand API 21 . 34Clay API. 38Soft Clay (Jeanjean) . 41Weak rock . 43Strong Rock . 45CPT Sand (Suryasentana and Lehane) . 47CPT Clay (Truong and Lehane) . 50CPT Carbonate sand (Dyson and Randolph) . 52CPT Auto . 54User defined curves. 56Theoretical . 58Forming the stiffness matrix . 58Solution procedure . 61Validation . 64Outline. 64Validation of Clay (API) static . 64Validation of Clay (API) Cyclic . 67Validation of Sand (API) . 68Elastic behaviour of the pile . 70Elastic perfectly-plastic behaviour of the pile . 73References . 75

4LIST OF TABLESTable 1: Input parameters for Elastic perfectly-plastic (calculated) . 31Table 2: Input parameters for “Elastic perfectly-plastic (user defined)” . 33Table 3: Rate of increase of initial modulus of subgrade reaction with depth . 35Table 4: Input parameters for Sand API21 . 37Table 5: API Clay p-y data for short-term static loading . 38Table 6: p-y data for equilibrium conditions of cyclic loading . 38Table 7: Parameters for Clay API . 39Table 8: Input parameters based on consistency . 39Table 9: Parameters for Soft clay (Jeanjean) . 41Table 10: Input parameters for Weak Rock . 43Table 11: Parameters for strong rock . 46Table 12: Input parameters for CPT Carbonate Sand (Dyson and Randolph) . 53

5LIST OF FIGURESFigure 1: Example problem . 9Figure 2: the PROJECT tab active . 10Figure 3: Project definition . 10Figure 4: Pile position and total length . 11Figure 5: Section 1 Pile properties . 12Figure 6: Enter elevation of pile Section 2 . 13Figure 7: Parameters for Pile section 2 . 14Figure 8: defining the ground surface elevation . 15Figure 9: Soil parameters for “Layer 1” . 16Figure 10: Soil parameters for “Layer 2” . 17Figure 11 specifying the elevation of the ground water table . 17Figure 12: Specifying a “Surcharge” load . 18Figure 13: Specifying a prescribed displacement . 19Figure 14: Specifying a prescribed rotation . 19Figure 15: Reaction “springs” . 20Figure 16: Default solution settings . 21Figure 17: Screen shot with RESULTS selected . 22Figure 18: Pile geometry definition . 23Figure 19: Soil stress and pore pressure definition . 25Figure 20: Screen shot of an Excel file generated by LAP . 26Figure 21: Elastic perfectly plastic moment-curvature response . 29Figure 22: p-y response for Elastic perfectly plastic spring model . 30Figure 23: Brinch Hansen Kq values. 31Figure 24: Brinch Hansen Kc values. . 32Figure 25: variation of cohesion with in a soil layer. 32Figure 26: API Sand 21 coefficients . 35Figure 27: Nomralised form of API Sand 21 implemented in LAP . 37Figure 28: Form of p-y curve for Clay API . 39Figure 29: Normalised Soft clay (Jeanjean) p-y curves . 42Figure 30: Form of p-y curve for weak rock. 44Figure 31: py curve for strong rock . 45Figure 32: CPT Sand normalised pu with normalised qc for a range of d/D ratios . 47Figure 33: CPT sand normalised p-y response . 48Figure 34: Normalised p-y response for a range of normalised qc values and d/D ratios . 49Figure 35: CPT clay py models normalised pu with rigidity index for a range of d/D values . 50Figure 36: CPT clay normalised p-y response for Ir 200 and a range of d/D values . 51Figure 37: Defining the variation of R with depth for CPT Carbonate (Dyson and Randolph) . 52Figure 38: Screen shot from web application of CPT Auto input options . 54Figure 39: Roberston Fr-Qt classification chart from LAP . 55

6Figure 40: screen shot of data assembled in excel with data under the yellow cells pasted into LAP directly . 56Figure 41: screen shot of user specified p-y pasted into LAP. 57Figure 42: Illustration of beam spring finite element model . 58Figure 43: Members stiffness relationship for spring elements . 59Figure 44: Member stiffness for beam elements . 59Figure 45: Member degrees of freedom for beam-spring system . 60Figure 46: accounting for non-linear springs . 62Figure 47: Screen shot of API clay test case. 64Figure 48: the computed normalised ultimate pressure against elevation . 65Figure 49: comparison of normalised model response with API curve . 66Figure 50: Computed pressure profile at each load increment compare with ultimate pressure . 66Figure 51: normalised computed py curves for Clay (API) cyclic . 67Figure 52: comparison of LAP computed pu and API equations . 68Figure 53: Comparison of LAP computed p-y curves for all depth and all load increments with normalised APIequations . 69Figure 54: Screen shot of pile cantilever problem . 70Figure 55: Screen shot of pile deflection for cantilever problem . 71Figure 56: Screen shot of the Load-displacement summary plot for the cantilever test problem . 72Figure 57: Cantilever pile with elastic perfectly plastic pile . 73Figure 58: Results for elastic perfectly plastic pile . 74

7GENERAL INFORMATIONLAP: (Lateral Analysis of Piles) is a web-based application for calculating the behaviour ofvertical piles subjected to lateral loads.Pile properties: The pile is modeled with structural beam elements and can be assigned eitherlinear-elastic or elastic-perfectly plastic material properties. Up to ten different pile sectionscan be included in a single analysis.Soil p-y curves: The soil is modeled as a collection of independent (Winkler) springs. The loaddisplacement behaviour of the springs can be specified using parameters for common p-ycurves. Users can also specify their own p-y curves by pasting in tabulated data.Loading: Pile loads can be specified as combination of horizontal forces, applied moments,prescribed horizontal displacements and prescribed rotations at any location along the pile. Asurcharge load can be applied on the ground surface adjacent to the pile. This has the effect ofincreasing the total vertical stress in the soil by an amount equal to the value of the surchargeload.Reaction springs: Horizontal and rotational reaction springs can also be included. Thesereactions spring may represent structural elements that resist movement of the pile. They arenot intended to represent the soil.Non-linear FEA in the cloud: The program solves for the pile response using non-linear finiteelement analysis. The calculations are performed on a cloud server. The the programs runefficiently on all devices connected to the internet.Saving and sharing input data: Input data is saved as a project, with a Project Name and aRun ID. Projects are stored on a database server and users can access their projects across allof their devices. Projects can also be shared among users.Auto-documentation: All input and output data can also be atomically downloaded in an Excelfile (provided the device you are working on has Microsoft Excel installed). This allows forvery rapid and thorough offline documentation.Access: The program can be accessed by following links from www.geocalcs.com/lap. Usersregister their details. The program does not require the installation of any software other thana common web browser.

8TERMS OF USELAP was developed by Dr James P. Doherty at the University of Western Australia. Theprogram is made freely available for use as a research and teaching tool. For commercialapplications, users must seek permission directly by contacting james.dohery@uwa.edu.au .Although testing and validation of the LAP has been undertaken, it cannot be guaranteed thatthe program is free of errors. The developer offers no warrantee in relation to the use of LAPwhatsoever and the developer cannot be held liable for errors that are based on the use of LAP.

9GETTING STARTEDOutlineThis section of the manual uses an example to provide some basic guidance for setting up andanalysing a job in LAP. The example is illustrated in Figure 1 along with key input dimensions.zTop of pile elevationz 2mWater tablez 1.5mTop of Clay z 1mPileSection 1ClayTop of Pile Section 2z -2mTop of Sand z -5mPilelengthL 17mPile Section 2SandFigure 1: Example problemProjectImmediately after in the “PROJECT” menu item will be active (Figure 2) and two options willbe available. That is, we either load an old project (or manage old jobs including sharing themwith other users) by selecting the “Load/share project” button or we “Create a new project”.

10Figure 2: the PROJECT tab activeIn this exampl

Pile properties: The pile is modeled with structural beam elements and can be assigned either linear-elastic or elastic-perfectly plastic material properties. Up to ten different pile sections can be included in a single analysis. Soil p-y curves: The soil is modeled as a collection of independent (Winkler) springs. The load-