P 14。 When the structural strength reaches more than 75% of the design strength, the abutment and wall should be backfilled;
P35。 The foundation of gravity retaining wall should be backfilled in layers in time after the strength of foundation mortar reaches 75% of the design strength;
P36。 When the concrete or mortar strength of the retaining wall reaches 75% of the design strength, the back of the wall should be backfilled in time.
P38。 Adjacent piles can only be excavated after the concrete strength of anti-slide pile reaches 75% of the design strength;
P 184。 The formwork on the top surface of cast-in-place beam with movable formwork shall be removed only after the compressive strength of concrete reaches 75% of the design strength.
P 187 demoulding shall be carried out during prefabrication of cantilever assembled segments, and when there is no provision in the design, it shall be carried out after the concrete strength reaches 75% of the design strength.
P247 When the open-cut tunnel is backfilled manually, the concrete strength of arch ring should not be less than 75% of the design strength. Mechanical backfill, arch ring concrete should not be less than the design strength.
Second, the requirement for strength in the bridge is basically 80%.
P 135。 Fresh concrete should be poured four weeks before the arrival of the ice age, and it should not be frozen before the strength reaches 80% of the unexpected strength level.
P 142。 When the pretensioning method is used, the strength and elastic modulus of concrete should meet the design requirements. If there are no regulations in the design, the strength of concrete should not be less than 80% of the design strength and the elastic modulus should not be less than 80% of the elastic modulus of concrete for 28d.
P 144。 When the post-tensioned prestress is tensioned, the strength and elastic modulus should comply with the design regulations, and the unspecified strength should not be less than 80% of the design strength, and the elastic modulus should not be less than 80% of the 28d elastic modulus of concrete.
P 170。 Drainage in the steel box should be carried out after the back cover concrete meets the design requirements or reaches the setting strength of more than 80%.
P 176。 In the process of demoulding, transportation, storage and installation of assembled beam and slab members, the concrete strength should not be less than the hoisting strength specified in the design, and should not be less than 80% of the design strength when there is no provision in the design.
P 176。 Assembled beam-slab components and components installed in layers and sections can be installed only after the installation components are fixed reliably and the joint strength with greater stress reaches 80% of the design strength.
P 177 Post-tensioned prestressed concrete beam and slab moves after grouting on precast pedestal, and the strength of grouting body shall not be less than 80% of the design strength.
P 188。 For segments assembled with wet joints, prestress can only be applied when the joint strength reaches more than 80% of the design strength.
P283 sign supporting structure shall be installed after the foundation strength reaches more than 80% of the design strength and is approved by the supervision engineer.
Third, the arch bridge is basically 85% of the project.
P 127 The arch frame of cast-in-place arch ring should be removed within the design period. When there is no provision in the design, the concrete strength of arch ring should reach 85% of the design strength.
P 128, the mortar stone arch bridge can be unloaded only after the mortar strength reaches 85% of the design strength.
P 198。 After the closure of the arch bridge meets the design requirements or reaches 85% of the design strength, the fasteners will be removed in stages according to the principle of symmetrical balance.
P 198。 When the strength of arch rib joint and arch rib transverse connector meets the design requirements or reaches 85% of the design strength, the frame can be removed.
P206。 After the concrete strength of the bottom web of the arch ring reaches 85% of the design strength, the cover plate can be installed, the steel bar can be laid, and the cast-in-place roof plate can be installed.
P206。 When the box arch is prefabricated, when the strength reaches 85% of the design strength, it can be hoisted and transported to the storage place for storage.
P209 For arch rings with a span of more than 2m, when laying in a circle, the lower circle should be laid and closed first, and then the upper circle should be laid after the joint mortar strength reaches more than 85% of the design strength.