关键词: 水泥土搅拌桩, 养护温度, 等效龄期, 无侧限抗压强度, 调整系数

Abstract: In-situ cement-soil mixing pile differs markedly from laboratory cement-soil standard test in terms of curing temperature and pile forming technology, making it difficult to reasonably reflect the compressive strength of cement-soil mixing pile on site. In view of this, we established a strength model for cement-soil mixing pile which considers the curing temperature by introducing the equivalent age theory and the adjustment coefficient to reflect respectively the influences of temperature history and pile forming technology. First of all we conducted compressive strength test on cement-soil under three different curing temperatures (5 °C, 20 °C, and 40 °C). We further estimated the activation energy of cement-soil by the least square method and identified the parameters of the compressive strength model using the optimization algorithm. Finally, we obtained the adjustment coefficient of the model based on the foundation temperature and the detected strength of the cement-soil mixing pile in a typical sluice project. Results implied that the compressive strength of cement-soil at the same age augmented with the rising of curing temperature. Pile forming technology has remarkable impact on the strength of cement-soil. The present model well reflects the development law of the strength of cement-soil mixing piles.

Key words: cement-soil mixing pile, curing temperature, equivalent age, unconfined compressive strength, adjustment coefficient