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To solve the problems of multi-objective control, objective quantification difficulties and computational complexity existing in the construction management, the construction system reliability was introduced into the project management. The process of construction project was divided into several units of work based on system decomposition theory. And the reliability of each unit of work was calculated. Then, the system reliability was optimized by the improved firefly algorithm. To avoid that the basic algorithm is highly depended on the initial solution and easy to fall into local optimum at later stage, the dynamic population firefly algorithm was proposed. Engineering practice shows that the improved algorithm has higher convergence speed and accuracy of optimization. The study provides a novel method for effective construction management.

With the rapid development of the national economy of China, an increasing need for transportation facilities is becoming a serious challenge that the existing traffic system has to meet. Thus, the highway transportation capacity development level assessment has important significance in theory and in practice. In order to overcome the current defects of stronger subjectivity and experience in common assessment methods, the entropy weight and the TOPSIS method were introduced and employed to the comprehensive assessment of highway transportation capacity development. Shannon information entropy was applied to determine the weight value of each index in the comprehensive assessment model. After determining the index weight, the result of comprehensive assessment was obtained through the TOPSIS method. Finally, the effectiveness and feasibility of the proposed method were shown by application in practice.

Ant colony algorithm is widely used in recent years as a heuristic algorithm. It provides a new way to solve complicated combinatorial optimization problems. Having been enlightened by the behavior of ant colony's searching for food, positive feedback construction and distributed computing combined with certain heuristics are adopted in the algorithm, which makes it easier to find better solution. This paper introduces a series of ant colony algorithm and its improved algorithm of the basic principle, and discusses the ant colony algorithm application situation. Finally, several problems existing in the research and the development prospect of ACO are reviewed.

Prestressed Concrete Cylinder Pipe (PCCP) is a kind of high quality composite pipe, whose mechanical behavior is not uniform because of its complicated structure and work condition. The mechanical model is established in PCCP working stage, based on the elastic plane strain theory of axisymmetric multilayer cylinders and the mechanism of the ring-like strands action. Then the design method of prestress is put forward according to the crack control. The stress is analyzed with finite-element analysis in the condition of different hydraulic pressures, and also the method is amended compared with the finite-element analysis. It is indicated that the design method of prestress is reasonable compared with both domestic and international specifications.

According to the size of the projector function to evaluate the merits of the program, Projection Pursuit method is applied to real estate investment decision-making by using the real coding based on Accelerating Genetic Algorithm (RAGA) to optimize the Projection Pursuit Classification (PPC) process and a wide range of indicators value was projected linearly. The results are reasonable and verified with an example. At the same time, the subjective of the target weight can be avoided. It provides decision-makers with comprehensive information on all the indicators of new ideas and new methods

In order to overcome the premature convergence defect of the basic particle swarm optimization (PSO) algorithm and provide an effective method for shape and sizing optimization of truss structure, an improved PSO was proposed. The random direction method was employed to produce high-quality initial population, the fuzzy system was applied in the dynamic adaptive adjustment of parameters of the PSO, and the Metropolis criteria were used to improve the performance of PSO. Then, the improved PSO was introduced to the truss structure shape and sizing optimization design. Engineering practice and comparison with the other optimization algorithms show that the algorithm has good convergence and global searching capability. The study provides a promising algorithm for the structural optimization.

To overcome the shortcomings of the Fuzzy Set which is a common safety assessment measure, the unascertained measure was proposed and the credible identification was set up after the introduction of the basic knowledge of the Unascertained Sets including the essential difference between the Unascertained Sets and the Fuzzy Sets. Then, the method was introduced into the safety assessment of offshore jacket and modular loadout. Finally, engineering practice showed that the method proposed here can complete the safety assessment systematically and scientifically without any assumption. The work has significance in theory and practice for safety assessment.

To management the risk of International Project Contracting where the chance and risk are accreted and the risk is bigger than the domestic engineering, the paper sets up the comprehensive evaluation system and a model of risk assessment by using the unascertained set for evaluating the risk of the international project contracting. Finally, the practicality and feasibility of the model are illustrated by the engineering practice.