Construction method for performing humidification and ultra-high energy level treatment on collapsible loess foundation with height of 25m or more

Abstract

The invention belongs to the technical field of foundation treatment of civil engineering and particularly relates to a construction method for performing humidification and ultra-high energy level treatment on a collapsible loess foundation with thickness of 25m or more. The construction method comprises the following steps: 101, determining the collapse elimination depth and a remnant collapse control value of the foundation; 102, performing reverse upward calculation from the bottom of a collapse soil layer on a treatment area according to the remnant collapse control value so as to performcollapse accumulation calculation, wherein when calculated collapse is less than or equal to the control value, depth at the moment is needed treatment depth, namely the collapse elimination depth; 103, determining water injection humidification depth; 104, determining the depth of a water injection hole; 105, determining dynamic compaction construction parameters; 106, designing a water injection system pipeline network and designing a water injection process; and 107, performing water injection humidification and ultra-high energy level dynamic compaction test construction, adjusting and optimizing the water injection and dynamic compaction construction parameters again according to a test result, and then, performing large-area application and construction. The construction method provided by the invention exceeds the limit depth of the maximum treatment depth of non-humidification ultra-high energy level dynamic compaction.

Description

technical field [0001] The invention belongs to the technical field of civil engineering foundation treatment, in particular to a construction method for treating collapsible loess foundations with a humidification ultra-high energy level of more than 25 meters. Background technique [0002] Collapsible loess is a kind of main regional rock and soil widely distributed in my country. After being soaked in water, collapsible loess will produce collapsible deformation under the pressure of its own weight and additional pressure, which will damage the upper buildings. Cracks in the house, uneven settlement damage, and serious collapse of the building are serious adverse geological phenomena. [0003] The treatment of collapsible loess generally adopts dynamic compaction method, compaction pile method, soil borrowing drilling, and long hammer compaction method. Among the three methods, the dynamic compaction method is the most economical and the process is simple. Generally, the ...

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Problems solved by technology

[0009] 2. As the water content decreases, the liquidity index of the soil gradually decreases. When the natural water content is less than the plastic limit, the liquidity index becomes negative, especially for the collapsible silty clay loess foundation. As the value increases, the hardness of the soil becomes greater and greater, making it more difficult to tamp the foundation

[0010] 3. The self-weight collapsible loess with a thickness of 25m or more cannot be constructed when compaction piles are used due to the high strength of the loess and the difficulty of pulling out the pipe.

Since the collapsibility below 10m without humidification cannot be improved or reduced, it is still difficult to meet the treatment requirements of the collapsible loess foundation standard

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