In the present paper, the estimation of limit unit bearing capacity qbL of axially loaded circular footings on sands based on cone penetration test cone resistance qc is examined. There are significant uncertainties in the calculation of bearing capacity using the bearing capacity equation. The selection of the value of the soil friction angle ϕ and of the equation for Nγ accounts for much of the overall uncertainty. The approach proposed in this study can reduce the uncertainties associated with the bearing capacity equation, as no estimation of ϕ or selection of an equation for Nγ is necessary. Instead, normalized limit unit bearing capacities qbL ∕ qc are calculated from non-linear finite element and cone penetration resistance analyses for various soil and footing conditions. Effects of the relative density DR , the lateral earth pressure ratio K0 , and the footing size are also addressed. It is observed that the normalized limit unit bearing capacity qbL ∕ qc decreases as DR increases and that this r...

The sustainable performance of foundations of various urban buildings and infrastructures is strongly affected by groundwater level (GWL), as GWL causes changes in the stress state within soil. In the present study, the components affecting GWL were investigated, focusing on the effects of precipitation and river stage. These components were analyzed using a six-year database established for hydrological and groundwater monitoring data. Five study regions for which daily measured precipitation, river stage, and GWL data were available were compared. Different periods of precipitation, geographical characteristics, and local surface conditions were considered in the analysis. The results indicated that key influence components on GWL are different depending on the hydrological, geological, and geographical characteristics of the target regions. River stage had the strongest influence on GWL in urban areas near large rivers with a high ratio of paved surface. In rural areas, where the paved surface area ratio and soil permeability were low, the moving average showed a closer correlation to GWL than river stage. A moving average-based method to predict GWL variation with time was proposed for regions with a low ratio of paved surface area and low permeability soils.

In this study, the lateral load–carrying capacity of micropiles was investigated focusing on the effect of micropile inclination. A series of model load tests was conducted for both single (SMP) and group (GMP) micropiles with various configuration conditions of inclination angle, load direction, and micropile spacing. To clarify the load-carrying mechanism of inclined micropiles, a finite-element (FE) analysis was performed. The lateral load–carrying capacity of inclined SMPs increased with $\theta$ up to 30° for $\delta =0°$ , whereas opposite trends were observed for $\delta =180°$ . The lateral load–carrying capacity of inclined GMPs increased continuously with $\theta$ owing to the fixity effect with micropile cap. From the results of FE analyses it was found that the main resisting components of inclined micropiles for the lateral load–carrying capacity are the passive failure zone and skin friction mobilized along the micropile surface. Design methods for single and group micropiles subjected to lateral loads were proposed. The values of regression coefficients were evaluated using the results from the model tests and FE analyses. To check the validity of the proposed methods, full-scale field load tests were conducted and used to compare measured and estimated load capacities. Estimated results obtained using the proposed method were in good agreement with measured results.

Most of the existing methods for estimating settlements of footings in sand have been developed for either isolated square footings or for strip footings. The literature contains limited information on settlement analysis of rectangular footings, and, as a result, there is no way to accurately account for the effect of the footing length-to-width ratio on settlement. Additionally, no practical method exists for considering the interaction between neighboring footings in settlement estimates. In this paper, we use Schmertmann’s framework to propose a method of settlement estimation that takes full account of both the footing length-to-width ratio and the proximity of neighboring footings. Three-dimensional nonlinear finite element analyses were performed for various multiple footing configurations. Plate load tests were performed in sands using both a single plate and two plates separated by various distances. The numerical and experimental results indicate that the shape of the footing (expressed through ...

Conventional methods for the estimation of the ultimate lateral pile load capacity are typically based on certain expressions of the lateral soil resistance pu and assumed distributions of the lateral soil pressure mobilized along the pile embedded depth. When soils are nonhomogenous, however, the application of conventional methods represents significant difficulties due to the nonlinear and irregular variation of pu with depth. In this study, a cone penetration test (CPT)-based methodology for the estimation of the ultimate lateral pile load capacity Hu was proposed, which can take full account of entire soil profile through the CPT cone resistance qc . A normalized correlation between qc and pu was proposed with correlation parameters corresponding to different existing methods. In order to validate the proposed CPT-based methodology, case examples of laterally loaded piles in various soil conditions were prepared and used to compare values of Hu from original and proposed methods. Calibration chamber ...