Increases in the global population and urbanization have made people's demand for rational development and utilization of urban underground space (UUS) increasingly urgent. The underground sewage treatment plant (USTP) plays an important role in sustainable urbanization as part of the UUS. Nevertheless, problems such as high operating costs and large safety hazards still restrict the development of the USTP. In this paper we intend to summarize the current application of the USTP, reflecting the specific and novel aspects of the USTP, and also some technology drawbacks and main process update problems, providing some development suggestions. To do this, essential information on USTPs globally is simply and clearly revealed under due diligence, providing a development process for the USTP and making a prediction for its future development. Furthermore, combined with the main treatment process and ecological value analysis, we give a valid view of the good application prospects of the USTP, which provides a reference for the future construction of USTPs.

This paper aims to manufacture recycled concrete hollow block (RCHB) which can be used for the masonry structure with seismic requirements. Five RCHB masonry walls were tested under cyclic loading to evaluate the effect of the axial compression stress, aspect ratio, and the materials of structural columns on the seismic performance. Based on the test results, the failure pattern, hysteresis curves, lateral drift, ductility, stiffness degradation, and the energy dissipation of the specimens were analyzed in detail. The results showed that with the increase of aspect ratios, the ductility of RCHB masonry walls increased, but the horizontal bearing capacity and energy dissipation of RCHB masonry walls decreased. With the increase of compressive stress, the bearing capacity and energy dissipation performance of RCHB masonry walls were improved, and the stiffness degraded slowly. The results also demonstrated that the RCHB masonry walls with structural columns, depending on whether the structural columns were prepared by ordinary concrete or recycled concrete, could increase the bearing capacity, ductility, and energy dissipation of specimens. The research confirmed that RCHB masonry walls could meet the seismic requirements through thoughtful design. Therefore, this study provided a new cleaner production for the utilization of construction waste resources.