【正文】 ks with more depth are pleted and are qualified after back filling of earthwork. If the equipment foundation is conducted inside a constructed building or near a building, the precautions shall be taken to protect the structure of building from settling and damaging. If there are some adjacent foundations with different depth, firstly the deep foundation shall be constructed. If the base of shallow foundation is disturbed, the measures shall be taken to treat the base. — 8 — After the acceptance of foundation pit, the construction of foundation shall start in time. If abnormal phenomena occur in the foundation pit due to interruption for a long time, it is required to treat and accept the foundation pit again. Before the installation of foundation bolt, preembedded parts and metal supporting frame, the grease, oxide and soil on their surface shall be cleared. The settlement observational point for equipment foundation shall be set in accordance with the design document and shall conform to the relevant regulations on the GBJ202 “Specification for the Construction and Acceptance of Base and Foundation Works”. The settlement observational time shall conform to the following regulations, if it is not stated in the design. 1） After the plete of grouting concrete and removing the diaphragm plate。 3） After installation of equipment。 6） The observational times shall be increased in special conditions. When the foundation is turned to installation of equipment, the strength of concrete shall conform to the following regulations: 1） For the equipment foundation of block type, it shall be no less than 75% of designed strength。 3） For the equipment foundation of tower type, it shall be 100% of designed strength。 Before the foundation is turned to installation, its axis, elevation and value of elevation shall be marked. — 9 — 3． Form panel, steel reinforcement and concrete works Formworks The installation scheme, as well as type, size and quantity of form panel shall be selected according to the construction drawing. The form panel shall be cleared and repaired before it is used. During installing the form panel, the joints shall be pactive. The contacting surface between the form panel and concrete should be coated with insulating agent before they are used. The partial form panel of foundation reached above of ground shall be coated with the insulating agent that is no pollution to concrete surface. During installation of the form panel, the foundation axis and outline shall be prepared on the concrete mattress or base plate. During install the column form panel on the frame foundation, the clean out shall be prepared at the bottom of the column form panel. The operating hole shall be prepared in each 2m of shaft of column form panel. During the construction of steel formwork, a form panel can be removed as a clean out or an operating hole where it is necessary. Where the section of structure is small, the steel reinforcement is dense, or the operation is difficult, the through operating hole shall be set, which the form panel shall be sealed while grouting concrete. The counterdraw bolt of M12 shall be set on both sides of form panel of walltype foundation. The space of counterdraw bolt can be laid by calculation, or according to the following table . Table Space of Counterdraw bolt Layout Side pressure of concrete（ kPa） Space of counterdraw bolt (mm) ≤ 20 ≤ 40 ≤ 60 If there are trenches for pipeline in the equipment foundation, during the installation of form panel of foundation, the precast concrete trench can be installed on the shaped steel supports and can be casted in place with the foundation concrete. The form panel and supports can be removed according to the following regulations, if — 10 — it is not required in design. 1） When removing the form panel, the strength of foundation concrete shall not be less than the parameters stipulated in the following table . Table Strength of Concrete of Foundation during Removing the Form Panel No. Type of structure Span of structure (m) Percentage of designed strength (%) 1 Panel (bottom form) ≤ 2 50 2~8 75 2 Beam (bottom form) ≤ 4 75 4 100 3 Cantilever beam (bottom form) ≤ 2 75 2 100 4 Block foundation — 40 2） The procedures of removing form panes shall be in reverse to the order of its installation. In general, firstly the side form panel shall be removed, then the bottom form panel shall be removed。 . Where there are two meshes of up and down in the foundation reinforcement, the steel bar and shaped steel can be made into the supports to locate the up mesh of steel reinforcement. The thickness of concrete cover for steel bar shall conform to the regulation on the GB50204 “Specification for the Construction and Acceptance of Concrete Structure Works”. The tolerance deviation for the concrete cover shall conform to the table . Table Tolerance deviation for the thickness of steel reinforcement cover (mm) No. Items Tolerance deviation 1 Foundation 177。 5 3 Panel wall 177。 2） Form panel and steel reinforcement。 2） Add the additives with functions of slowly setting or miniexpanding。 4） The water cement ratio is no more than 。 2） No less than one group per 50m3. The work qualities of equipment foundation shall conform to the following requirements: 1） No any defects of crack, honeyb and exposed bar occur。 20 Overall dimension of plane on convex 0 20 Dimension of plane on concave +20 0 4 Levelness (inclusive of the plane to be installed equipment) Per meter 5 Overall length 10 5 Side verticality Per meter 5 Overall height 10 6 Preembedded foundation bolt Elevation (top) +10 0 Central space (check both at the bottom and top)