Abstract: Socketing of bored piles in rock is always seen as a matter of debate on construction sites between consultants and contractors. The socketing depth normally depends on the type of rock, depth at which the rock is available below the pile cap and load carrying capacity of the pile. In this paper, the review of field load test data of drilled shaft socketed in weathered limestone conducted using conventional static pile load test and dynamic pile load test was made to evaluate a unit shaft friction for the bored piles socketed in weathered limestone (weak rock). The borehole drilling data were also reviewed in conjunction with the pile test result. In addition, the back-calculated unit shaft friction was reviewed against various empirical methods for bored piles socketed in weak rock. The paper concludes with an estimated ultimate unit shaft friction from the case study in Qatar for preliminary design.
Abstract: In order to improve the efficiency and accuracy of the pressure hull structure, optimization of underwater vehicle based on response surface methodology, a method for optimizing the design of pressure hull structure was studied. To determine the pressure shell of five dimensions as a design variable, the application of thin shell theory and the Chinese Classification Society (CCS) specification was carried on the preliminary design. In order to optimize variables of the feasible region, different methods were studied and implemented such as Opt LHD method (to determine the design test sample points in the feasible domain space), parametric ABAQUS solution for each sample point response, and the two-order polynomial response for the surface model of the limit load of structures. Based on the ultimate load of the structure and the quality of the shell, the two-generation genetic algorithm was used to solve the response surface, and the Pareto optimal solution set was obtained. The final optimization result was 41.68% higher than that of the initial design, and the shell quality was reduced by about 27.26%. The parametric method can ensure the accuracy of the test and improve the efficiency of optimization.
Abstract: Full - Scale Accelerated Loading System, one part of
“the Eleventh - Five - Year National Grand Technology Infrastructure
Program" is a facility to evaluate the performance and service life of
different kinds of pavements subjected to traffic loading under full -
controlled environment. While simulating the environments of frigid
zone and permafrost zone, the accurate control of air temperature, road
temperature and roadbed temperature are the key points and also
aporias for the designment. In this paper, numerical simulations are
used to determine the design parameters of the frozen soil simulation
system. At first, a brief introduction of the Full - Scale Accelerate
Loading System was given. Then, the temperature control method of
frozen soil simulation system was proposed. Finally, by using finite
element simulations, the optimal design of frozen soil simulation
system was obtained. This proposed design, which was obtained by
finite element simulations, provided significant referents to the
ultimate design of the environment simulation system.