碱渣物理力学特性及动强度试验研究

Experimental research on physical and mechanical properties and dynamic strength of soda residue

碱渣是采用氨碱法生产纯碱过程中产生的工业废渣,将碱渣填垫作为工程地基既可以有效降低工程成本,也可以解决其堆积占地和环境污染问题。要将碱渣填埋作为地基大量应用于工程实际,首先要解决碱渣相关物理力学特性和承载力问题。以天津港原状碱渣为研究对象,开展了基本物理力学特性试验和动三轴试验,确定碱渣的基本物理力学指标,探究循环荷载作用下考虑超固结比影响的碱渣强度的发展规律。试验结果表明,碱渣具有含水量大、密度小、孔隙比大、压缩性高的特点。循环荷载作用下,正常固结碱渣的强度随着动应力比的增大而减小,超固结碱渣的强度随动应力比的增大先增大后减小,超固结碱渣的强度不随动应力的增大而单调变化。研究成果可为碱渣作为工程地基应用提供参考。

Soda residue is the industrial waste residue produced during the production of soda ash by the ammonia-soda method.Using soda residue as the foundation of the engineering can not only effectively reduce the engineering cost,but also solve the problems of accumulation and environmental pollution.In order to use soda residue as a foundation for a large number of engineering practice,the physical and mechanical properties and bearing capacity of soda residue must be solved first.Based on the undisturbed soda residue from Tianjin Port,the basic physical and mechanical properties tests and dynamic triaxial tests were carried out to determine the basic physical and mechanical indexes of soda residue,and to explore the development law of soda residue strength considering the effect of overconsolidation ratio under cyclic loading.The test results show that the soda residue has the characteristics of large water content,small density,large void ratio and high compressibility.Under cyclic loading,the strength of normally consolidated soda residue decreases with the increase of dynamic stress ratio,and the strength of over-consolidated soda residue increases first and then decreases as the dynamic stress ratio increases.The strength of overconsolidated soda residue does not change monotonously with the increase of dynamic stress.The research results can provide reference for the application of soda residue as engineering foundation.