Research on Red-Bed Soft Rock Engineering Properties and Foundation Appraisement of Construction Engineering in Guangzhou

Based on the methods of geological drilling, literature research, induction and statistics, the site investigation of an old industrial park reconstruction project in Haizhu District of Guangzhou city was completed. The landform, formation lithology, structure and hydrogeological characteristics were systematically identified. Combined with indoor test and in-situ test, the variation rules of physical and mechanical parameters of argillaceous siltstone with different weathering degrees in the site were analyzed, and the evaluation results were given. The engineering suitability and the foundation stability are evaluated. The results showed that the weathering of soft rock makes the statistical standard values of compression coefficient, compression modulus, direct fast shear cohesion and internal friction angle of rock and soil decrease. Under the saturated state, the average value of strongly weathered argillaceous siltstone is 1.51 MPa, and that of moderately weathered argillaceous siltstone is 6.2 MPa. The strength of soft rock is low after softening with water, and the differential weathering of rock mass is strong. There are great differences in rock strength, local differences between fully and strongly weathered rock surfaces, and great changes in thickness. The weathering is extremely heterogeneous, in which the influence of structure, lithology, fissures and groundwater played a key role. The foundation is generally in a stable state, and the site is suitable for the construction of the project. The research results can provide reference for similar geotechnical engineering investigation and design.