A Comprehensive In Situ Investigation on the Reinforcement of High-Filled Red Soil Using the Dynamic Compaction Method

High-filled red soil typically lacks sufficient bearing capacity, which can pose significant challenges when constructing building foundations. One economical and effective method for the reinforcement of high-filled red soil is the dynamic compaction (DC) method. However, the design parameters for reinforcing high-filled red soil using the DC method are largely based on experience, which indicates the significant value of field results of related engineering practice. In this paper, we report a field study that was carried out to investigate the effect of impact energy on the treatment of super-high-filled ground with red soil in southwestern Yunnan, China, where three pilot DC tests were designed and conducted with three different impact energies (4000 kN·m, 8000 kN·m and 15,000 kN·m). To evaluate the reinforcement effect and optimize the DC operational parameters, a series of in situ tests, including settlement monitoring, standard penetration tests, dynamic penetration tests, surface wave velocity tests and plate-load tests, were carried out. Furthermore, the improvement depth of DC was discussed. The results of the field study show that the characteristic value of the ground bearing capacity of the three test zones could reach 250 kPa, which coincides with the design requirement, although the improvement depth of testing zone III fails to reach the required depth. This study helps to improve the in situ recycling of high-filled soil, thereby promoting the sustainable development of engineering construction.