共检索到 5

Basement-addition for existing building plays a crucial role in alleviating urban land shortage. However, the disturbance induced by basement-addition construction to the stability of the building foundation and superstructure has not been well understood. The objective of this paper is to investigate the performance of typical structural components involved in a basement-addition project. They include the columns in the superstructure, the strip foundation beneath the columns, and the piles used for reinforcing the strip foundation during excavation. A three-dimensional finite element model is established, using a basement-addition project of an existing building as a case example. The calculated results by the finite element model align well with the measured data, confirming the model's validity. Based on this, the stress and deformation characteristics associated with the selected structural components during basement-addition construction are investigated. The findings indicate that the stress and deformation characteristics of the structural components are highly sensitive to the depth of the foundation pit excavation, with these characteristics intensifying as excavation depth increases. The excavation of the initial soil layer has the most significant impact. Upon completion of the excavation, the maximum settlement values for the strip foundation (SF), column foot, and pile are -18.6 mm, -13.79 mm, and -16.1 mm, respectively. The underground diaphragm wall (UDW) exhibits maximum vertical and horizontal displacements of 7.6 mm and 18.1 mm, respectively. The pile primarily experiences compressive internal forces, with its axial force showing little sensitivity to excavation depth. The pile's maximum bending moment, shear force, and axial force are 21.2 kNm, 34 kN, and -2,481 kN, respectively. The internal forces and deformations of structural components demonstrate distinct spatial distribution patterns, with values increasing closer to the foundation pit's center. Therefore, it is crucial to enhance monitoring of the displacement and internal forces of the central components of the foundation pit to prevent engineering accidents. These research findings will contribute positively to the design optimization and construction guidance of similar engineering structures.

期刊论文 2025-04-14 DOI: 10.1038/s41598-025-97939-8 ISSN: 2045-2322

In recent years, numerous studies highlighted the crucial role of the soil-structure interaction (SSI) in the seismic performance of basement structures. However, there remains a limited understanding of how this interaction affects buildings with basement structures under varying site conditions. Based on the three-dimensional (3D) numerical analysis method, the influence of the SSI on the seismic response of high-rise steel frame-core wall (SFCW) structures situated on shallow-box foundations were investigated in this study. To further investigate the effects of the SSI and site conditions, three types of soil profiles-soft, medium, and hard-were considered, along with a fixed-foundation model. The results were compared in terms of the maximum lateral displacement, inter-story drift ratio (IDR), acceleration amplification coefficient, and tensile damage for the SFCW structure under different site conditions, with both fixed-base and shallow-box foundation configurations. The findings highlight that the site conditions significantly affected the seismic performance of the SFCW structure, particularly in the soft soil, which increased the lateral deflection and inter-story drift. Moreover, compared with non-pulse-like ground motion, pulse-like ground motion resulted in a higher acceleration amplification coefficient and greater structural response in the SFCW structure. The RC core wall-basement slab junction was a critical region of stress concentration that exhibited a high sensitivity to the site conditions. Additionally, the maximum IDRs showed a more significant variation at incidence angles between 20 and 30 degrees, with a more pronounced effect at a seismic input intensity of 0.3 g than at 0.2 g.

期刊论文 2024-11-01 DOI: 10.3390/buildings14113522

Intense summer rainstorms can result in short-term urban flooding, leading to localized groundwater level rise and subsequent floor cracking and leakage in basements. Rational control of the surrounding water level is crucial for addressing existing basement leaks caused by short-term urban flooding. In this study, a combined approach of interception and seepage control using waterproof curtains and negative-pressure wells is proposed. Four different scenarios were considered, and experimental and numerical investigations were conducted on a 1.2 m x 1.2 m x 1.1 m model. The study analyzed the influence of factors such as water content, pore water pressure, soil properties, waterproof curtain insertion depth, and length of the filter in the negativepressure well on controlling the upward water level in the basement. The results showed that the installation of waterproof curtains alone can impede rainwater infiltration into the basement, delaying its penetration by approximately 48 h. The combined approach of interception and seepage control outperformed the sole use of waterproof curtains, with the reduction in water level becoming smaller as the insertion depth of the waterproof curtain increased. The reduction in water level decreased at a slower rate with increasing waterproof curtain insertion depth. The recommended waterproof curtain insertion ratio was equal to or greater than 83.5 %, while the filter length ratio in the negative pressure well should be less than 64 %. Compared to natural seepage drainage, negative-pressure pumping could maintain the basement floor's water content within the initial range 32 h earlier. The water-blocking and depressurization effect is best in sandy soil and worst in clay. Water-blocking and depressurization provide a new approach for controlling the uplift caused by summer urban waterlogging, especially offering a new method for controlling leaks in the basement.

期刊论文 2024-10-01 DOI: 10.1016/j.istruc.2024.106751 ISSN: 2352-0124

In the present study, centrifuge tests for small-scale specimens were performed to investigate the dynamic soil pressure of the basement of buildings subjected to seismic ground motions. To investigate the effect of the embedded depth of basement, a deep basement model fixed to rock (model 1) and a shallow basement model embedded in soil (model 2) were tested. The soil pressures acting at the front wall (Dynamic soil pressure, DSP) and back wall (Soil pressure at back wall, BSP) were measured. Under the Northridge earthquake (with PGA(b) = 0.33 g), DSP of Model 1 (fixed based model) reached 100 kPa showing an increasing linear distribution from bottom to top. The DSP profile was similar to the profile of relative displacement between the basement and soil. Interestingly, BSP decreased to 0 as a gap occurred between the soil and basement wall. On the other hand, in the case of model 2 with a smaller depth, the relative displacement between the basement and soil was smaller due to the influence of flexible base. As a result, DSP (<20 kPa) was smaller and BSP was greater than those of the deep basement model fixed to rock. The tested soil pressures were compared with the predictions of existing models.

期刊论文 2024-09-09 DOI: 10.1080/13632469.2024.2337849 ISSN: 1363-2469

In building structures, exterior basement walls should resist the soil pressure type earthquake load transmitted by the ground. Thus, the structural performance of the exterior basement walls is affected by in-plane seismic performance as well as out-of-plane load resistance. In the present study, for better constructability and costeffectiveness of the exterior basement walls, conventional reinforced concrete walls were replaced with precast hollow core slab (HCS) panels. To investigate the in-plane earthquake load resistance of HCS for exterior basement walls, cyclic lateral loading test and numerical analysis were performed on four HCS panels with inplane double curvature. The test and analysis results showed that the structural behavior of the HCS panels was significantly affected by the panel layout. In the test specimens using a single panel, flexural compression failure occurred at the bottom of the panel, and shear friction damage occurred at the upper and lower parts of the panel. In the test specimens using double panels, failure mode was governed by direct shear. The loadcarrying capacity of the test specimens using double panels was greater than two times that of the test specimens using a single panel, because the load transfer changed from flexure into direct shear in the wall specimens using double panels. Further, to use HCS panels for exterior basement walls, a design method for prediction of inplane seismic performance and yield displacement of HCS panels was proposed.

期刊论文 2024-05-01 DOI: 10.1016/j.istruc.2024.106478 ISSN: 2352-0124
  • 首页
  • 1
  • 末页
  • 跳转
当前展示1-5条  共5条,1页