Full Steel Top-Down Basement Construction Method
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Solution Overview
Problem
The traditional top-down construction method for multi-storey basements is inefficient due to high material input, storage requirements, and excavation limitations, leading to prolonged construction periods and difficulties in deformation control and water stop management.
Innovation Solution
A top-down construction method using a full steel structure, which includes constructing a diaphragm wall and pre-embedding steel beams, allowing for simultaneous excavation and construction without waiting for concrete curing, and utilizing steel cantilever structures for material handling, reducing material lifting times and storage needs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional top-down construction method with concrete structures is used, then structural stability is ensured, but construction cycle is prolonged due to concrete curing time requirements
Solution Approach 1:
The patent changes the material parameter from concrete to steel structure, fundamentally altering the construction timeline. Steel structures eliminate the curing time constraint inherent in concrete, allowing immediate subsequent construction activities while maintaining structural stability through steel's inherent strength properties.
Solution Approach 2:
The patent implements preliminary action by pre-assembling steel components above ground before installation. Steel beams, columns, and trusses are manufactured and prepared in advance, enabling rapid installation during basement construction without waiting for material delivery or on-site assembly, thus compressing the construction cycle.
2Ease of manufacture
If traditional bent frames and ground formwork are used, then reinforced concrete structures can be constructed, but material storage requirements and transportation work increase significantly
Solution Approach 1:
The patent extracts and eliminates traditional temporary support systems (bent frames, ground formwork) by replacing them with a permanent steel structure system. This removes the need for extensive material storage of formwork components and their subsequent dismantling and disposal, significantly reducing material quantity requirements.
Solution Approach 2:
The steel structure serves multiple functions simultaneously: it acts as temporary support during construction, permanent structural framework, and eventual load-bearing system. This multi-functionality eliminates the need for separate temporary and permanent structures, reducing overall material consumption.
3Manufacturing precision
If earth intake is arranged in basement area with sequential construction, then structural quality can be maintained, but excavation efficiency decreases due to net height limitations
Solution Approach 1:
The patent applies dimensionality change by installing steel beams and trusses in three-dimensional space above the excavation zone. This allows earth intake operations to proceed vertically and horizontally without being constrained by the net height limitation of traditional horizontal formwork systems, significantly improving excavation efficiency while maintaining structural quality through the steel framework.
4Reliability
If bottom plate construction is completed before basement earth intake closure, then structural integrity is ensured, but construction progress is slowed and professional engineering interpenetration is restricted
Solution Approach 1:
The patent introduces dynamics by enabling flexible, non-sequential construction sequencing. The steel structure provides sufficient support to allow basement earth intake closure to proceed before bottom plate completion, and permits overlapping of professional engineering works (waterproofing, mechanical, electrical) with structural construction, thereby improving overall construction progress while maintaining structural integrity through the adaptable steel framework.
Data Source
AI summary
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.