Karst Cave Concrete Pouring via Hollow Drill Stem
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current construction methods for pouring concrete in karst caves are inefficient, leading to high material consumption, lengthy construction periods, and excessive procedures due to the need for complete filling and repeated drilling, which increases costs and reduces bearing capacity.
Innovation Solution
A method involving a hollow drill stem with a reaming drill bit and a thin-walled steel shell, where low-slump plain concrete is pumped into the cave without full filling, and the drill bit is lifted with concrete to form frustum-shaped piers, reducing material usage and improving bearing capacity by socketing into stable rock, while using mechanized equipment to shorten construction time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the karst cave is completely filled with sand, gravel and cement, then the bearing capacity of the foundation is improved, but the material consumption and construction cost increase significantly
Solution Approach 1:
The invention extracts only the essential function of filling (providing bearing capacity) and achieves it through a targeted approach: drilling holes to stable rock stratum and pouring concrete only in those locations, rather than completely filling the entire karst cave. This eliminates unnecessary material consumption while maintaining foundation bearing capacity.
Solution Approach 2:
The karst cave treatment is segmented into discrete drilling holes rather than continuous filling. Each hole is drilled to the stable rock stratum and filled with concrete independently, allowing precise material placement only where structural support is needed, thereby reducing overall material consumption.
2Strength
If repeated drilling and hammering are performed to form piles with large filling coefficient, then the bearing capacity is improved, but the construction procedures become excessive and the construction period lengthens
Solution Approach 1:
The invention merges multiple separate operations (drilling, hammering, repeated drilling) into a single integrated process: one drilling operation creates the hole, concrete is poured directly into the hole, and the process repeats for the next hole. This eliminates redundant procedures and significantly improves construction efficiency while achieving the required bearing capacity.
Solution Approach 2:
The construction process maintains continuous useful action by drilling each hole and immediately pouring concrete without intermediate hammering or waiting periods. This continuous flow of drilling and pouring operations eliminates idle time and redundant steps, thereby shortening the construction period.
3Stability of the object's composition
If the karst cave is completely filled with materials, then the foundation stability is improved, but the construction cost increases due to excessive material usage
Solution Approach 1:
The invention applies local quality by providing enhanced material (concrete) only at specific locations where structural support is needed - namely, in holes drilled to the stable rock stratum. The surrounding karst cave space remains unfilled, avoiding unnecessary material consumption while maintaining foundation stability through strategically placed concrete pillars.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method significantly reduces material consumption and construction time, enhances the bearing capacity of the foundation by forming concrete piers without full cave filling, and improves the efficiency of the construction process by utilizing mechanized equipment.
Implementation Method 1
pumping the commercial concrete into the hollow drill stem through the connecting pipe
Implementation Method 2
pumping the water into the karst cave through the hollow drill stem to clean the karst cave
Data Source
AI summary
The present application discloses a construction method for pouring concrete in a karst cave. Concrete streaming is pumped into a hollow passage of a drill stem, then opens the one-way openable sealing cover with a pre-tensioned spring on a reaming drill bit and enters the karst cave to complete pouring of the concrete. When the karst cave is relatively low, low-slump plain concrete mixed with quick-setting agents is injected through a drilling rig and the hollow drill stem to form a concrete pier; when the karst cave is relatively high, the hollow drill stem is sleeved into a thin-walled steel shell, and the thin-walled steel shell is synchronously sunk into the drilled hole while drilling, enters the karst cave and is socketed into a stable rock stratum, then concrete is pumped into the thin-walled steel shell from the bottom of the pile, and finally, a reinforcement cage is inserted to form a cast-in-place pile. Compared with the existing karst cave treatment methods, the construction method according to the present application can greatly reduce the consumption of materials, improve the mechanization of construction, simplify the construction process, shorten the construction period and reduce the engineering cost, and the cast-in-place pile with thin-walled steel shell, formed when the karst cave is relatively high, can further improve the bearing capacity of the foundation.