A simplified elastic analysis of tunnel-piled structure interaction

In urban areas, engineers often need to assess tunnelling-induced displacements of piled structures and the resulting potential for damage. This paper presents an elastic study of tunnel-pile-structure interaction through Winkler-based Two-Stage Analysis Methods (TSAMs), focusing on structural displacements resulting from tunnel excavation beneath piled frames or simple equivalent beams. Comparison of results with 3D finite element analyses shows that the simple TSAM models are able to provide a good assessment of tunnelling-induced building displacements. Parametric analyses highlight the role of tunnel-pile interaction and the superstructure (stiffness, configuration, and pile-structure connections) in the global response of the tunnel-soil-building system. In particular, the effect that key parameters have on deflection ratios and horizontal strains are investigated. Results illustrate how piled foundations increase the risk of structural damage compared to shallow foundations, whereas structural stiffness can reduce building deformations. Flexural deformations are predominately induced by tunnel excavations beneath piles whereas horizontal strains at the ground level are negligible when a continuous foundation is included. Furthermore, it is illustrated that results based on buildings modelled as equivalent beams can differ considerably compared to when they are modelled as framed structures. Simple design charts are provided to estimate horizontal strains and deflection ratio modification factors based on newly defined relative axial and bending stiffness parameters which account for the presence of the piles.This work was supported by the Engineering and Physical Sciences Research Council (EPSRC) [grant number EP/K023020/1, EPSRC Doctoral Training Award]

Self-reported use of complementary and alternative medicine (CAM) products in topical treatment of diabetic foot disorders by diabetic patients in Jeddah, Western Saudi Arabia

<p>Abstract</p> <p>Background</p> <p>There is little published on current Saudi diabetic patients' practices when they are exposed to foot disorders such as open wound, ulcer, and skin cracks. These factors are usually influenced by local culture and communities beliefs. The aim of the current study was to identify the pattern of patients' use of CAM products in dealing with diabetic foot disorders topically in a group of diabetic patients.</p> <p>Findings</p> <p>A Cross-sectional descriptive study of a representative cohort of diabetic patients living in Jeddah, Saudi Arabia was designed. A pre-designed questionnaire to identify local diabetics' practices in dealing topically with foot disorders including open wound, chronic ulcer, and skin cracks was designed. Questionnaire was administered by a group of trained nutrition female students to diabetics face to face living in their neighborhood. A total of 1634 Saudi diabetics were interviewed. Foot disorders occurred in approximately two thirds of the respondents 1006 (61.6%). Out of the 1006 patients who had foot disorders, 653 reported trying some sort of treatment as 307 patients (47.1%) used conventional topical medical treatment alone, 142 (21.7%) used CAM products alone, and 204 (31.2%) used both treatments. The most commonly used CAM product by the patients was Honey (56.6%) followed by Commiphora Molmol (Myrrh) in (37.4%) and Nigellia Sativa (Black seed) in (35.1%). The least to be used was Lawsonia inermis (Henna) in (12.1%). Ten common natural preparations used topically to treat diabetic foot disorders were also identified.</p> <p>Conclusions</p> <p>The use of CAM products in topical treatment of diabetic foot disorders is fairly common among Saudi diabetic patients. Honey headed the list as a solo topical preparation or in combination with other herbs namely black seeds and myrrh. The efficacy of the most common products needs further research.</p