4.2　Turbine Proper Foundation

4.2.1　The foundation handed over for erection shall meet the following conditions:

1　The geometric dimensions，reserved openings and embedded parts of the foundation shall comply with design requirements.

2　Strength of foundation concrete shall be 70%of the design strength and over.

3　Settlement observation shall comply with requirements.

4　Water stop shall be in place on roofing of turbine building.

5　Safety facilities such as foundation railing，passages and openings shall be complete.

6　The surface shall be flat，free of defect such as cracking，hole，honeycomb，pitting or exposed rebar.

7　The plastering of generator air chamber and duct shall be flat and smooth，without peeling of loose dust；anti-corrosive treatment shall be made for metal platform and stairs inside.

8　The longitudinal centerline of foundation opening shall be perpendicular to the transversal centerline of condenser and generator pedestal.

9　The foundation dimensions shall not restrict the connection and expansion of upper and lower components of the unit.

10　The deviation of equipment foundation concrete load bearing surface from design value should be-10mm-0mm.

11　The permissible deviation of generator air duct concrete top elevation from design value is 10mm.

12　The anchor bolt holes shall be cleaned，the permissible deviation of bolt hole centerline from foundation centerline is 10mm，the vertical permissible deviation of bolt hole wall is 10mm，the holes shall be through，without cross bar or sundries；the concrete plane of bolt holes for contact with anchor bolt backing plate shall be flat.

13　For direct embedded anchor bolts and parts，the materials，type，longitudinal and transversal centerlines and elevation shall comply with design，the center permissible deviation of bolts and embedded parts is 2mm，the elevation permissible deviation of embedded parts is 3mm，the permissible deviation of anchor bolt top elevation from design value is+5mm-+10mm，and if the anchor bolt elevation design has not taken into account the shaft system up-rising inclination deviation，correction shall be made as per the shaft system center drawing during erection.

14　The longitudinal and transversal centerline and elevation permissible deviation of the embedded longitudinal and transversal pins and anchoring plates is 3mm，their top elevation shall be corrected according to the shaft system center drawing provided by manufacturer；the center permissible deviation of embedded MSV and CRV supports is 2.0mm，with elevation permissible deviation as 3.0mm，the surface shall be flat；the elevation permissible deviation of relevant embedded parts is 1.0mm.

15　The longitudinal and transversal centerlines，sectional and elevation dimensions of cantilever beam，and the architectural structure dimensions at the installation locations of generator and condenser shall comply with the design requirements.

16　The reserved holes for generator and exciter lead-outs，ventilation ducts，oil pipes and hydrogen and water cooling pipes shall comply with design requirements in dimensions and relative locations.

17　Sundries in the vibration isolating joint between foundation and operation platform shall be cleaned off.

18　The bottom of pipe trenches shall be flat，and the sloping direction and gradient，centerline，bottom elevation and sectional dimensions shall comply with design requirements.

4.2.2　Settlement observation for turbine proper foundation shall be performed as follows:

1　First measurement shall be made after expiration of foundation curing period，as original data.

2　Before and after installing the turbine casing and generator stator in place.

3　Before secondary grouting for steam turbine and generator.

4　Before and after the complete trial run.

4.2.3　For collapsible loess geological structure，the number of settlement measurements can be increased.

4.2.4　Equipment installation must not be continued in case of apparent irregular change in the measured data every two days in the leveling，alignment and centering of turbine due to foundation settlement.

4.2.5　For turbo-generator unit foundation with elastic vibration isolating device，the height before and after spring releasing shall be checked and measured as required in technical documents，and the locking of spring shall be checked in the following phases:

1　After expiration of foundation curing.

2　Before release of vibration isolating spring.

3　After release of vibration isolating spring，and before connection of turbo-generator unit coupling.

4.2.6　As required on-site，inspection and measurement of spring locking condition can be added as follows:

1　Before location of generator stator.

2　After location of generator stator.

3　Centering of the wholly assembled casing.

4　After welding of LP casing with condenser.