Correction: Calculation of displacements and internal forces of anchored retaining piles.

[This corrects the article DOI: 10.1371/journal.pone.0243659.].

Calculation of displacements and internal forces of anchored retaining piles.

Pile-anchor retaining structures are widely used in excavation engineering. The evaluation of lateral displacements, the internal forces of piles are extremely important for the performance of the structure. Most of the existing methods are empirical, semiempirical or FEM methods, while analytic calculation methods for this evaluation are rare. This paper presents an analytic method to calculate the displacements and internal forces of anchored retaining piles based on the existing design code. In the calculation method, the singular function is applied to evaluate the effect of segmented loading on the deflection of a beam with a nonuniform cross section. The load concentration function, expressed by the singular function, can describe the segmented load and be integrated without a complicated procedure for determining the integral constants. The method is applied to a structure in Wenzhou, China, and the calculation results are compared to the field measurement results. This method is only valid for pre-failure predictions.

Evaluation of the factors influencing the housing safety awareness of residents in Shanghai.

Shanghai has experienced rapid urbanization and has a serious housing aging problem. The situation of urban housing safety management needs to be strengthened. However, in China, housing safety management (HSM) is just in its beginning stage and it lacks thorough research. Housing safety awareness is one of the most significant aspects of housing safety management. Therefore, in order to investigate the housing safety awareness of Shanghai residents, this paper investigates the safety attitudes of residents living in housing of different ages using consulting questionnaires and Statistical Package for Social Science (SPSS) software. The results show that in Shanghai, the residents lack an understanding of housing management law, policy, and awareness of safety use and have low willingness to buy commercial insurance. Based on these results, the factors that affect the safety awareness of Shanghai residents are summarized as follows: (1) asymmetric information; (2) assessment of the safety status of the premises; and (3) differences in house users.

The Extent of Heavy Metal Pollution and Their Potential Health Risk in Topsoils of the Massively Urbanized District of Shanghai.

Urbanization and industrialization increase the concentrations of heavy metals in soils, which affect human health. A total of 127 topsoil samples were collected from the massively urbanized and industrialized district of Shanghai: Baoshan District. The sampling sites were isolated based on the land-use practice: industrial area, roadside area, residential area, and agricultural area. The absolute concentrations of heavy metals (Zn, Cr, Ni, Mn, Cu, Pb, and Cd) were determined using atomic absorption spectrometry and compared with Shanghai and the National soil background values. The geoaccumulation index (Igeo) and Nemerow pollution index were used to determine the existence and severity of the pollution of heavy metals. Enrichment factor (EF) analysis, spatial variability of pollution, and multivariate statistical analyses also were employed to determine the anthropogenic loading of heavy metals, their spatial dependency, and correlation among their sources, respectively. Moreover, potential ecological risk and human health risk [carcinogenic risk (RI) and noncarcinogenic hazard (HI)] were evaluated. The average concentration of all the metals (accounted as 229, 128, 56, 719, 55, 119, and 0.3 mg kg-1 for Zn, Cr, Ni, Mn, Cu, Pb, and Cd, respectively) was many folds higher than the background values. The indices depicted that the pollution exists in all the sites and severity decreases in the following order: industrial soils > roadside soil > residential soils > agricultural soils. However, Zn, Pb, and Cd showed high levels of pollution in all the soils. The EF values suggested that the majority of heavy metals are anthropogenically loaded; spatial variability showed that the pollution is more concentrated in Songnan town; Pearson's correlation, principal component analysis (PCA), and cluster analysis suggested different sources of origin for the majority of the heavy metals. RI of Cr and Pb ranged between 2.8E-04 and 2.7E-07. However, HI was site-specific (only for Cr, Pb, Mn), and most of the sites were in Songnan town. This study could be used as a significant piece of information for management purposes to prevent heavy metal pollution and to protect human health.