钙质砂的胶结性及对力学性质影响的实验研究

Experimental Investigation on Cementation of Calcareous Sand and Its Basic Mechanical Characteristics

对南海钙质砂进行了三轴实验研究,重点针对不同胶结情况下的力学性质,如不同胶结材料和含量的变化对强度和应力应变特性的影响等。研究表明,钙质砂具有与陆源砂不同的性质,它的内摩擦角高达48°,远大于一般陆源砂的35°左右;在低围压下钙质砂表现出剪胀性,但随围压增加剪胀性降低;利用硅酸盐水泥作为胶结材料效果较好;随着水泥含量的增加,钙质砂试样的强度增加。

Tri-axial experiment was carried out to study the basic mechanical properties of calcareous sand exploited from South China Sea. The attention was focused on the cementation effect of different materials on the mechanical properties, e. g. , the effect of cementation materials content and type on the strength and stress-strain characteristics. Results show that the calcareous sand has many different properties from the terrigenous sand, such as its internal friction angle （48°） is much larger than that of terrigenous sand （35° approximately）, and the dilatancy is obvious under low confined pressure but disappears gradually with the increase of confined pressure. Portland cement is a good cementation agent. The strength of calcareous sand increases with the increase of Portland cement content.