酶诱导碳酸钙沉淀联合高岭土固化砂的物理力学特性试验研究

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中图分类号：TU411.2 文献标志码：A 文章编号：2096-6717（2025）06-0086-09

Abstract： To enhance the solidification efect of enzyme-induced calcium carbonate precipitation （EICP） technique，this study employed EICP combined with kaolin to treat standard sand for solidification.Two experimental variables were set： the amount of kaolin added and the curing time.Macroscopic and microscopic experiments were conducted on solidified sands under diferent variable combinations.The experimental results revealed that the unconfined compressive strength of the EICP-combined kaolin solidified sand continued to increase with the increase in kaolin content and curing time.The compresive strength after curing with 4% kaolin content for 14 days was 722.19kPa ，which was 13.15 times that of pure EICP solidified sand. The calcium carbonate precipitation rate did not continue to increase with curing time or kaolin content.The efficiency of calcium carbonate precipitation was highest when cured with 3% kaolin content for 7 days.As the kaolincontent increased，the porosity first decreased and then increased，with the minimum porosity observed at a kaolin content of 2% . The pore structure of the solidified sand before and after adding kaolin changed from being dominated by medium pores （accounting for over 90% ）to being dominated by small pores （around 80% ）， indicating a significant improvement in the pore structure.The calcium carbonate crystals deposited between the particles of the EICP-combined kaolin solidified sand were mainly aragonite spheres，which were stacked and filled in the interstices between sand particles and covered the surface of sand particles，significantly enhancing the bonding effect between sand particles.

Keywords： soybean urease；calcium carbonate precipitation; kaolin clay； standard sand

传统土体加固技术有挤密砂桩、强夯、振冲、高压喷射注浆等，与这些技术相比，微生物诱导碳酸钙沉积（MICP）和脲酶诱导碳酸钙沉积（EICP）是一类更加绿色生态的新兴生物土体固结技术。（剩余12508字）