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Inserting a prestressed high-intensity concrete pipe pile into a cement–soil mixing pile can form a new composite pile named the composite foundation with stiffened deep cement mixing (SDCM) pile. The Huanghuai alluvial stratum in China is selected to carry out the in situ test for the SDCM pile, and the bearing capacity of the SDCM pile is tested by the slow-speed maintenance load method. The results show that for an SDCM pile with dense silt and fine sand as the bearing layer, the characteristic value of bearing capacity can reach 2,300 kN, which means an SDCM pile with a length of 8.0 m meets the load requirement of a general high-rise building. Further analysis shows that the SDCM pile saves more than 40% of the cost compared with the traditional CFG pile and has better quality control advantages at the same time. This research can provide basic data and design references for similar site foundation projects.

The current expansion of building structures has created a demand for efficient and smart surface quality evaluation at the acceptance phase. However, the conventional approach mainly relies on manual work, which is labor-intensive, time-consuming, and unrepeatable. This study presents a systematic and practical solution for surface quality evaluation of indoor building elements during the acceptance phase using point cloud. The practical indoor scanning parameters determination procedure was proposed by analyzing the project requirements, room environment, and apparatus. An improved DBSCAN algorithm was developed by introducing a plane validation and coplanar checking to facilitate the surface segmentation from the point cloud. And a revised Least Median of Square-based algorithm was proposed to identify the best-fit plane. Afterwards, the flatness, verticality, and squareness were evaluated and depicted using a color-coded map based on the segmented point cloud. The experiment on an apartment showcases how the system improves the information flow and accuracy during building acceptance, resulting in a potentially smart acceptance activity. [ABSTRACT FROM AUTHOR]

In order to investigate the seismic performance of a rubber-modified soil isolation layer, a three-dimensional finite element model was constructed using finite element analysis software, utilizing a two-story frame structure as the engineering background. Nonlinear dynamic time history analysis and comparisons were performed against the seismic performance of the structure. The evaluation was based on several parameters, including the contact area of the base, the thickness of the rubber-particle-modified soil isolation layer, ground motion records with varying amplitudes, and seismic frequency spectrum characteristics. The research findings indicate that the implementation of a rubber-modified soil isolation layer effectively mitigates the peak acceleration, horizontal displacement, and shear stress of the frame structure. This not only enhances the seismic performance of the structure but also enlarges the contact area of the base. Increasing the thickness of the rubber-modified soil isolation layer will effectively decrease the peak acceleration, horizontal displacement, and shear stress of the structure during seismic events. The effectiveness of the isolation provided by the rubber-modified soil layer improves as the intensity of the ground motion record increases. [ABSTRACT FROM AUTHOR]