During deep foundation pit support construction, backfilling of foundation trenches is often constrained by conditions, space, and other factors, resulting in loose backfill soil that affects the seismic performance of tall buildings and can even lead to loss of serviceability. To address this, construction companies continue to seek technological breakthroughs. In order to effectively solve the backfilling problem, the Zhengzhou Niezhuang · Agile Jiangshan Yunan South Garden Project, after extensive verification and practice, successfully introduced the ready-mixed fluidized stabilized soil technology to replace the high-cost, hard-to-maintain plain concrete construction method.

What is ready-mixed fluidized stabilized soil?

Ready-mixed fluidized stabilized soil is a mixture prepared by mixing various types of discarded spoil, soil hardening agent, and water in a certain proportion to meet specified performance indicators. This technology uses a small amount of inorganic cementitious material to bind soil particles and employs chemical methods (such as soil stabilization admixtures) to activate the soil particles, promote stabilization reactions, and improve and enhance the performance of the hardened soil body (strength, water stability, and impermeability).

Construction process of ready-mixed fluidized stabilized soil

01. Soil sampling and soil quality inspection

Clay, silty clay, sandy silt, etc. are used (organic matter content less than 5%, moisture content shall meet requirements, particle size not greater than 50 mm).

02. Mixing

The stabilizer slurry and soil are fed into a mixer and mixed into a stabilized soil mixture.

03. Layered pouring

Considering factors such as the waterproofing construction progress of the basement exterior wall and site conditions, pouring should preferably be carried out in blocks and layers.

04. Curing

After each layer is poured, cover it with plastic film for curing. The initial and final setting times are 6 h and 12 h, respectively. The upper layer pouring operation should be carried out after the lower layer has reached final setting.

Process control:

① Before backfilling, the trench must be cleaned. The use standards and quality inspection of relevant materials shall be strictly controlled. The strength of the stabilized soil must meet the drawing design requirements before use;

② Specimens used to test the strength of stabilized soil shall be randomly sampled at the pouring site;

③ Construction shall be carried out strictly in accordance with the construction plan, technical disclosure, construction specifications, and other requirements;

④ Construction process control shall be strengthened. For example, during rainy season construction, drainage measures and the safety of construction personnel shall be ensured.‍

Applications and advantages

Applications:

① Backfilling of foundation trenches for underground utility tunnels and deep building foundations;

② Used as reinforcement bodies in composite foundations to form stabilized soil pile-wall structures serving as water-stop curtains;

③ Used as construction cushion materials and for stabilized floors;

④ Used as base course materials for municipal roads or construction roads, etc.‍

Advantages:

① Adapts to local conditions, fast construction speed, and high safety;

② Efficient, economical, and low-carbon;

③ Extremely high flowability, self-compacting properties, and impermeability;

④ Wide range of applications.‍‍

In actual construction, the Zhengzhou Niezhuang · Agile Jiangshan Yunan South Garden Project has proven the safety, practicality, and economy of the ready-mixed fluidized stabilized soil construction technology, and the construction company is now promoting its use. The successful application of this technology proves the project's own capability and strength in technological innovation and efficiency creation. In the future, the construction company will continue to encourage projects to explore innovative process technologies, focus on technological efficiency creation, and solve construction challenges!