The paper examines the influence of soil strength and stiffness on the end resistance mobilised by a cone or displacement pile in a two-layered soil profile (i.e. strong soil overlying or underlying weak soil). The investigation involved a series of numerical analyses that idealise pile/cone penetration assuming the spherical cavity expansion analogue. It is shown how the end resistance mobilised by a penetrometer in a dense sand (i.e. strong soil) varies with the number of penetrometer diameters (D) from a weak soil (assumed here to be either a loose sand or soft clay), and depends on the ratio of the steady-state penetration resistances of the strong and weak layers. The penetrometer resistance in the weak soil is not affected by an adjacent strong layer at penetrations greater than 2D. A design procedure based on a numerical parametric study is proposed, and this is subsequently shown to compare well with centrifuge test data and with previous numerical research.

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The multiple-travelling salesman problem (MTSP) is a computationally complex combinatorial optimisation problem, with several theoretical and real-world applications. However, many state-of-the-art heuristic approaches intended to specifically solve MTSP, do not obtain satisfactory solutions when considering an optimised workload balance. In this article, we propose a method specifically addressing workload balance, whilst minimising the overall travelling salesman's distance. More specifically, we introduce the two phase heuristic algorithm (TPHA) for MTSP, which includes an improved version of the K -means algorithm by grouping the visited cities based on their locations based on specific capacity constraints. Secondly, a route planning algorithm is designed to assess the ideal route for each above sets. This is achieved via the genetic algorithm (GA), combined with the roulette wheel method with the elitist strategy in the design of the selection process. As part of the validation process, a mobile guide system for tourists based on the Baidu electronic map is discussed. In particular, the evaluation results demonstrate that TPHA achieves a better workload balance whilst minimising of the overall travelling distance, as well as a better performance in solving MTSP compared to the route planning algorithm solely based on GA.

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The shortage of field measurements to examine existing predictive methods for pipe piles in clay prompted an experimental programme in Shanghai, China, in which displacements and stresses were measured in the vicinity of two pipe piles during their installation in a soft lightly overconsolidated clay. The test programme was also conducted to assist assessment of the installation effects associated with a recently patented cast-in-place concrete pipe pile, referred to as the PCC pile. The field measurements are compared with existing predictive methods such as the shallow strain path and cavity expansion methods (SSPM and CEM). The SSPM is shown to be the most suitable for the prediction of ground displacements, although the more straightforward CEM can provide realistic predictions of radial movements when calculations are performed using a solid pile with an area equivalent to that of the annulus of the pipe pile. Installation-induced excess pore pressures remote from pipe piles are also shown to be well predicted using the same cavity expansion method combined with this equivalent radius, while changes in lateral total stress display a faster degradation than that of the theoretical predictions. The paper provides verification of an expedient means of assessing installation disturbance due to undrained pipe pile installation.

This paper presents a simultaneous localization and mapping (SLAM) method that utilizes the measurement of ambient magnetic fields present in all indoor environments. In this paper, an improved exponentially weighted particle filter was proposed to estimate the pose distribution of the object and a Kriging interpolation method was introduced to update the map of the magnetic fields. The performance and effectiveness of the proposed algorithms were evaluated by simulations on Matlab based on a map with magnetic fields measured manually in an indoor environment and also by tests on the mobile devices in the same area. From the tests, two interesting phenomena have been discovered; one is the shift of location estimation after sharp turning, the other is the accumulated errors. Whist the latter has been confirmed and investigated by a few researchers, the reason for the first one still remains unknown. The tests also confirm that the interpolated map by using the proposed method improves the localization accuracy.

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