Horizontal Pressurized Dewatering Well for Sand Clay Strata
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Solution Overview
Problem
Current dewatering methods for deep and large foundation pits, particularly in water-rich strata with interbedded sand and clay layers, are ineffective, leading to poor deformation control, structural failures, and environmental damage due to inadequate drainage, which is exacerbated by the use of traditional tube well dewatering techniques.
Innovation Solution
A large-diameter horizontal pressurized long dewatering well method involving accurate positioning of horizontal wells and air ducts within the aquifer, using PVC pipes and air compressors to enhance water flow and counteract settlement deformation, ensuring the bearing capacity of soil nails or anchors is maintained.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional tube well dewatering is used in water-rich strata with interbedded sand and clay layers, then the dewatering system can be implemented, but the dewatering effect is poor and water level cannot be effectively controlled
Solution Approach 1:
The patent transitions from traditional vertical tube wells to horizontal dewatering wells that extend into the aquifer layer. This dimensional change allows the wells to directly intercept groundwater flow in the sand layer, bypassing the low-permeability clay layers that block vertical dewatering, thereby significantly improving water discharge efficiency
Solution Approach 2:
The patent applies different materials and structures to different parts of the dewatering system: screen sections are placed in high-permeability sand layers for water intake, while impermeable sections are positioned in clay layers to prevent infiltration. This localized differentiation optimizes water collection while maintaining system reliability
2Object-affected harmful factors
If drain pipes are inserted on slopes with traditional methods, then some water drainage is achieved, but it only addresses symptoms and makes limited contribution to controlling groundwater
Solution Approach 1:
Instead of surface-level drainage that only addresses visible water accumulation, the patent implements horizontal wells that extend into the groundwater table. This subsurface intervention directly targets the source of water accumulation, enabling effective groundwater control rather than merely managing surface symptoms
Solution Approach 2:
The patent introduces horizontal well casings and screens as intermediary structures that facilitate controlled water removal from the aquifer. These intermediaries enable selective water extraction while maintaining soil stability, providing reliable groundwater control that surface drainage cannot achieve
3Productivity
If horizontal drilling is performed in sand soil layers containing aquifer, then accurate positioning and rapid water discharge are achieved, but the complexity of construction equipment and process increases
Solution Approach 1:
The horizontal well construction is divided into manageable segments: vertical access shaft excavation, horizontal casing installation, screen section placement, and backfilling. This segmentation allows complex horizontal drilling to be performed using standardized equipment and procedures, reducing overall construction complexity while maintaining high water discharge productivity
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 provides precise and rapid water discharge, maintaining soil nail anchor capacity and reducing settlement deformation, effectively transforming 'inexhaustible pumping strata' into a dewatered area, thereby preventing structural failures and environmental damage.
Implementation Method 1
connecting the air ducts with the air pipe of the air compressor through a reducing joint, so as to inflate and pressurize the aquifer, which facilitates the water in the aquifer to flow to the drain pipes more quickly
Implementation Method 2
gathering water in a collecting well for pumping out and draining
Data Source
AI summary
Disclosed is a pumping method of a large-diameter horizontal pressurized long dewatering well for inexhaustible pumping strata. Clay layers and sand soil layers are determined according to construction positions of foundation pits, horizontal holes are drilled in the sand soil layers with a drill rig with simultaneous casing, and after the designed depth is reached, horizontal wells are placed, the horizontal wells are located above the junction of the clay layers and the sand soil layers, and the horizontal wells comprise drain pipes and air ducts, the drain pipes and the air ducts are located at the same elevation, each air duct is located between the two drain pipes, and the air duct is connected with the air pipe of the air compressor to deliver and pressurize, so as to facilitate water in the strata of aquifer to gather into the drain pipes.