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Telescopic jib is the key load-bearing component for both truck crane and all-terrain crane,seriously affect hoisting capacity of crane. Different stress feature or structural feature produce different affects on the hoisting capacity of telescopic jib. In order to study the mechanism and levels of different factors,multiple telescopic jib models with different factors are built based on nonlinear finite element method. Adopting Arc-length method to analysis structural nonlinear deformation in the whole course,the impact degree for hoisting performance of material yield strength, load eccentricity, lap length of telescopic jib and the support position of lifting hydraulic cylinder are acquired respectively. The results shows: A finite element method combined with arc-length method can be used to analysis the buckling problem of nonlinear deformation of telescopic jib. All the above four factors have affect on the hoisting performance of telescopic jib, but the levels are different. By analyzing change law of impact factors, corresponding measure are adopted in practical deign to reduce its impact and to strengthen the capacity of resisting local buckling of the telescopic jib.

Erdaoya tunnel in the highway connecting Shiyan (Hubei province) and Manchuan, (Shanxi province) was studied in the study. Various problems occurred in the construction of the tunnel, including large deformation of surrounding rocks, cracks of preliminary supports and secondary linings as well as creeping down and collapse of surrounding rock masses along schistosity planes. In which, the most serious problem was large deformation of surrounding rocks, which not only dramatically delayed the normal construction progress of the tunnel, but also brought a huge challenge for the safety of builders. In order to solve this problem, detailed investigations were made on site in the study to reveal the regional geological, engineering geological and hydrogeological conditions of the tunnel. By conducting geo-stress measurement on site, the characteristics of geo-stress field of Erdaoya tunnel were analyzed from four aspects, including magnitudes of stress, coefficient of lateral pressure, orientation of stress and the relationship between magnitudes of geo-stresses and depths. By applying the DIPS software for interactively analyzing geological locator data, structure characteristics of rock masses were analyzed for preferred structural planes and schistosity planes in the tunnel site.Furthermore, the authors tested the physical and hydrological properties of the rock specimens collected on-site. So various physical properties (density, void fraction, and wave velocity) and water absorption hydrological property of schist were obtained, which provide underlying parameters support for the deformation and support of surrounding rocks of the tunnel.

In this paper, we propose a new method for shape modification of NURBS curves. For a given NURBS curve, we modify its one or more weights so that the curve passes through the point specified in advance. We convert this into an optimization problem and solve it by genetic algorithm. The experimental results show the feasibility and validity of our method.