STU1000, STU1800, STU2700 Sheet Piles

Material type Select the material of the sheet piles from the available drop-down list:

User defined, Steel, Concrete, Wood, Synthetic.The first tieback will be added in Stage 3 simultaneous with the excavation so click on the tab for Stage 3. Go to the Support menu and select Add Bolt. For an initial estimate, the anchor may be assumed to lie at a distance below the top of the wall equal to one-fourth to one-third of the exposed wall height. Section bottom level Enter the vertical co-ordinate of the bottom of the sheet piling, in relation to the reference level. You will see the Add Bolt dialog. Ensure the Bolt Property is Bolt 1 and ‘Install at Stage:’ is 3. STU1000 SHEET PILING will automatically determine the value of the material factor γM as given in the Dutch norm, except for User defined for which γM must be entered by the user.penetration and anchor force, it will be necessary to consider several anchor positions to arrive at the optimal combination.Use several sections if the bending stiffness varies along the vertical axis of the STU1000 and STU 2700 sheet piling. Note: Sheet piling length may not be larger than 100 m.

The steel sheet piling anchor force calculated in the stability analysis was obtained from equilibrium of a typical 1-foot slice of the STU 2700 wall.Enter the bending stiffness of the section (product of Young’s Modulus E and moment of inertia I) per running meter if it has not already been imported from a library. Click OK to start entering bolt coordinates. Enter 10 , 17 for the first coordinate. Enter the coordinates 18 , 14 for the second point. Hit Enter to stop entering points. A variety of STU1800 anchor configurations are illustrated in Figure 2-2.

Acting width The acting width can be used when the effective width changes along the sheet piling (section 38.1.1).The model will look like this: To set the tieback properties, select Define Bolts from the Properties menu. For Bolt 1, change the bolt type to Tieback. Change the PreTensioning force to 20 kN and the Percent of Length to 40%.STU1800 or STU 1000 SHEET PILING uses the acting width as a multiplication factor for the sheet piling stiffness and all loads, supports and reactions, except the normal force, see Equation 27.1 in chapter 27 .In the actual system the anchor support is provided by discrete tie rods attached to the wall through wales and to another support mechanism (termed the "anchor" herein) at their ends and remote from the wall. Structural design of the tie rods and wales is discussed in Chapter 6.

Allow. Elas. charac. Moment Enter the characteristic value (i.e. without safety factors) of the allowable elastic moment M modification factor kmod to count for duration life of the synthetic material. For long term situation, the Dutch norm NEN 6702 prescribes a modification factor of 0.45 and for short term situation, a Capacities of some anchor configurations are discussed in the following paragraphs. The Bond Shear Stiffness and Bond Strength defaults are for a bolt anchored in bedrock.

Enter the partial safety factor γM, only if the User defined material type is selected. The soil strength parameters appearing in the equations associated with STU2700 anchor design should be consistent with the properties (S-case or Q-case) used for stability design.EL is used in the diagram of the moment to help the user to check if the maximum design moment is reached or not, see Figure 6.10 in section 6.3.1.Also, set the borehole diameter to 50 mm. This ensures that the ungrouted part of the bolt does not resist joint movement. Otherwise, the program will automatically apply the following factors (acc. to the corresponding Eurocode) to calculate the design allowable moment:In all cases the capacity of the STU 1800 anchor should be sufficient to develop the yield strength of the tie rods (Chapter 6).

Enter the STU2700 and STU 1800 reduction factor applied to the maximum allowable moment fMmax. This reduction factor can be for example factor βB < 1 as defined in article 5.2.2(2) of Eurocode 3 - Part 5 that takes account of a possible lack of shear force transmission in the interlocks of a sheet piling for single and double STU 1800 piles. Allow. Elas. design moment. Since this bolt is anchored in sand, reduce each by a factor of 10 as shown.The design value of the maximum allowable elastic moment Mdesign; EL is automatically calculated by the program using the following formula.