A floor plate assembly system for a top-down construction process includes an assembly pad formed around a vertical support core of the building. The assembly pad includes a top surface disposed at a ground level elevation of the building, and covers a footprint of the building. A plurality of tie-downs are attached to the assembly pad. A plurality of jack pedestals is positioned on the assembly pad, and are operable to support the floor plate, and raise and lower the floor plate relative to the assembly pad. Camber may be introduced into selective frame members by restraining the frame member to the tie-downs and extending a respective jack pedestal. The floor plates may be raised in their entirety to a work height with the jack pedestals to allow workers easy access to an underside of the plate.

Fabrication of a multi-story building includes fabricating floor plates at or near ground level, and lifting them to a final position on a vertical support core. A method for assembling one of the floor plates assembling a floor plate frame near ground level. Cambers are imparted into framing members based upon expected deflections, and metal decking is installed onto the floor plate frame. A plurality of permanent support points for the floor plate are determined, wherein the floor plate is attachable to the vertical support core at the permanent support points. First pedestals are installed between ground level and the floor plate frame proximal to the permanent support points for the floor plate. Hardenable material is dispersed onto the metal decking of the floor plate frame while the floor plate frame is lifted at the permanent support points.

A floor plate assembly system for a top-down construction process includes an assembly pad formed around a vertical support core of the building. The assembly pad includes a top surface disposed at a ground level elevation of the building, and covers a footprint of the building. A plurality of tie-downs are attached to the assembly pad. A plurality of jack pedestals is positioned on the assembly pad, and are operable to support the floor plate, and raise and lower the floor plate relative to the assembly pad. Camber may be introduced into selective frame members by restraining the frame member to the tie-downs and extending a respective jack pedestal. The floor plates may be raised in their entirety to a work height with the jack pedestals to allow workers easy access to an underside of the plate.

A method of constructing a building includes attaching a first portion of a roof structure to the yokes of a vertical slip form system. A derrick crane is positioned on top of the first portion of the roof structure. A vertical support core of the building is then formed with the vertical slip form system. The first portion of the roof structure and the derrick crane are raised with the vertical slip form system. The vertical slip form system is removed from the formed vertical support core of the building, and the first portion of the roof structure is then moved into a final position and attached to the vertical support core. The remainder of the roof structure and subsequent floor plates may then be constructed at ground elevation, raised into place, and attached to the vertical support core in a top-down, descending order.

A method of constructing a building includes constructing a vertical support core of the building, and attaching a climbing rail to an exterior of the vertical support core. The climbing rail includes holes spaced vertically. A first floor plate is constructed around a periphery of the vertical support core, at a ground elevation, and includes at least one connecting rail having vertically spaced holes. A climbing jack is attached to the climbing rail, and moved vertically upward on the climbing rail to raise the first floor plate to a first floor final elevation. The first floor plate is permanently attached to the climbing rail at the first floor final elevation by inserting a pin through aligned holes in the connecting rail and the climbing rail.

A floor plate for a building having a vertical support core is described, and includes first and second girders arranged in parallel and slidably disposed on opposed sides of the vertical support core. Each of the first and second girders includes a vertically-oriented web portion and a flange portion. The floor plate also includes a plurality of framing members, wherein each of the framing members includes a medial beam attached to first and second cantilevered beams. The medial beams are disposed between the first and second girders. The first and second cantilevered beams are threaded through apertures of the first and second girders and joined to the respective medial beam, and define first and second cambers. The first and second cambers are selected to achieve a flat horizontal surface on an upper surface of the floor plate when the floor plate is fixedly attached to the vertical support core.

A staircase assembly is installed in a multi-story building, including first and second flights of stairs that are hingably coupled to a landing, and a plurality of vertically-oriented columns coupled to the landing. The staircase assembly is assembled into a first liftable floor plate, and is disposed in a folded arrangement when the liftable floor plate is positioned at an assembly level elevation. The staircase assembly is disposed in an unfolded arrangement when the first liftable floor plate is positioned at a first design level elevation and a second liftable floor plate that is positioned at a second design level elevation below the first liftable floor plate.

A multi-story building includes a vertical support core that is disposed on a foundation, and a plurality of liftable floor plates. The liftable floor plates are fabricated at ground level and lifted into place on the vertical support core. The vertical support core includes vertically-oriented shear walls, and vertically-oriented columns disposed at corners thereof. Vertically-oriented first slots are formed between adjacent ones of the columns disposed at the corners. Each of the liftable floor plates includes girders, lateral framing members, diagonal framing members, and spandrels disposed at an outer periphery of the floor plate. The diagonal framing members are disposed diagonally in relation the lateral framing members and the first and second girders of the floor plate. The diagonal framing members extend through the first slots in the vertical support core and extend to one of the spandrels disposed at the outer periphery of the floor plate.

A building assembly system for fabricating a multi-story building is described, wherein the building includes a vertical support core arranged on a base. Lift jacks are arranged between a top portion and a bottom portion of the vertical support core, and a reusable bridle is suspended from the plurality of lift jacks and slidably arranged on the vertical support core. A floor plate is assembled onto the bridle at an assembly level that is proximal to the base. The plurality of the lift jacks are operable to lift the bridle and the assembled floor plate to a design elevation on the vertical support core, and are operable to lower the bridle to the assembly level on the vertical support core after the floor plate has been secured to the vertical support core at the design elevation.

A top-down construction method for a multi-storey basement with a full steel structure is provided, including: S1, constructing a diaphragm wall permanent structure; S2. conducting an open excavation, then constructing a first layer structural beam and slab; S3. conducting an underground excavation on an underground second layer earthwork, then constructing structural beam and slab and vertical shear wall on underground first layer; S4. excavating earthworks from an underground third layer to an underground N?1 layer, and constructing structural beams and slabs and vertical shear walls; S5. conducting the underground excavation on an underground N layer earthwork, and constructing a two-span structural steel beam; S6. conducting the underground excavation on earthworks of bottom plate layer, constructing remaining structural beams and slabs and vertical shear wall; S7. conducting the underground excavation on earthworks of bearing platform and water collection well; S8. constructing earth intakes of the podium and the basement.