Advanced Materials Research Vols. 1049-1050

Abstract: In cities and towns across the country the current movement is carried out like a raging fire, we often can see many from all kinds of news media in the land expropriation unfair now. The author collected the first-hand information by investigation, the analysis of relevant data. Considering the limitations of the data collected, this paper on the basis of the existing theory, discusses the interest distribution problems of local government, the village committee and the farmers whose land has been expropriated between these three subjects. Through the study of the subject, combined with the reality of research results, the reason the farmers' interests for farmers' cognition of the value of the land is not complete, relevant legal deficiencies, asymmetric information and government compulsory treatment. Then put forward the following 5 measures, use simple language and real data to put forward suggestions for perfecting the land requisition system.

Abstract: The continuity of concrete cellular slab was damaged by tubular hollow tubes which are arranged in slabs in parallel and the mechanical properties of slab exists anisotropy leading by different shapes of cross section in both directions of parallel and vertical to hollow tubes. Slab stiffness is weak greatly in direction of parallel to hollow tubes. For concrete cellular slab, the mechanical and deformation properties have been studied, the rigidity and stiffness ratio formula in both directions are been given. Orthotropic slab analogue method that is simplified calculation method for slab deflections are put out. The calculated results show that this method is adaptable and processes are simple. The calculated results are close to with engineering practices.

Abstract: In order to solve the problem of multi-index amalgamation on the reliability evaluation for tunnel lining with cracks, this paper based on extension theory, use matter element model theory to establish the matter element of the reliability evaluation for tunnel lining with cracks, use the dependent function to establish the relevance between matter element and reliability grade, combine the research result of the Beiru tunnel lining cracks disease to evaluate the reliability. The results show that it could consider the multi-index of the cracks to use the extension theory to evaluate the reliability of the tunnel lining with cracks, and the evaluation results are more scientific and reasonable. It is viable to use the dimensionless parameters to represent the crack geometry. In the K6, the treatment scheme is mechanical reinforcement. In the K2 and K3,the treatment scheme is surface sealing. The reliability evaluation results supply theory basis and technical guidance for the tunnel long-term health service and the disease treatment.

Abstract: This paper carried on the numerical analysis about the impact on soft soil ground seismic effect according to the buried depth and thickness of the soft interlayer, which took Jiangsu typical stratigraphic distribution and some engineering field as the prototype. In order to analyze the impact of buried depth and thickness of soft soil interlayers on the surface of the ground motion parameter, this paper combined with the formation parameters and calculated 3 sections which the thickness of soft soil interlayers were respectively 3m, 5m and 9m, in condition of the buried depth of the soft soil interlayer was constant. Choose ElCENTRO process curve for site seismic response analysis. The results showed that the influence of soft soil interlayer thickness on ground surface acceleration peak value was related with the location of weak interlayer. The influence of soft interlayer thickness on earthquake peak acceleration A_max and the eigenperiod T_g was more obvious; When the thickness of the soft interlayer increased, the earthquake peak acceleration decreased, the maximum speed decreased, and the maximum displacement increase; When the thickness of the soft interlayer increased, The maximum response spectrum decreased, the cycle of response spectrum peak increased, and the eigenperiod increased.

Abstract: In recent years, building density in the city is increasing as the promoting of urban modernization. Deep foundation pit excavation and bracing is a topic in geotechnical engineering, including strength and stabilization of soil mechanics, and transmutation and sedimentation of deep foundation, and common effect between soil and shoring structure. The paper based on the design and fabrication of indoor model test device. This paper respectively explored the destroy mechanism of cantilever and anchored sheet pile support structure on the soil pressure under the different loads, and comprehensively carried through cantilever and anchored sheet pile support test under four-grades excavation depth and four-grades load combination, and specially researched the transformation of soil pressure. At the same time, the piles spacing changed among 3cm, 4cm and 5cm. Theoretical results showed that the active earth pressure increased with the increase of load and excavation depth. Model test results showed that the earth pressure behind the piles increased with the increase of excavation depth and the load. The biggest earth pressure was 19.38kPa when loading 40kPa. The changing curves of soil pressure were similar when piles spacing was 3cm and 4cm. Earth pressure after the piles was negative when piles spacing exceeded 4cm, which illustrated that active earth pressure had changed into passive soil pressure.

Abstract: For the tunnel with high ground stress and soft surrounding rock, the deformation instability is the high frequency and great harm geological hazard. The supporting measure has become a important technique problem. This paper based on the Wuduxi tunnel, the characteristics of deformation and instability mechanism of surrounding rock and supporting structure are analyzed by means of the engineering geological investigation, theoretical analysis and field monitoring. The supporting measure include that using the steel floral tube to back up sidewall, adding support arch and filling foamed concrete, grouting reinforcement in basement. Finally, we use the field monitoring to check the supporting effect. The result shows that the supporting measure could achieve the desired treat effect and it has reference meaning to similar engineering.

Abstract: This paper mainly summarizes the structural design of mountain tunnels used to lay natural gas pipes in the 3rd pipeline project of natural gas transmission from west to east China according to the main requirement of laying gas pipes in mountain tunnels supported with concrete lining in light of geological conditions of surrounding rock, the designed parameters for tunnel lining are presented and meanwhile, the installation of gas pipe is also illustrated in the paper. The type of laying gas pipe and designing of tunnel support in mountainous regions proposed in this paper can provide practicable guidance to the design and construction of oil and gas pipe tunnels under similar circumstances.

Abstract: On the basis of ground geology and hydrogeology of an urban river, a municipal tunnel in which public pipes and cables are placed is designed to cross the river by means of open cut method. The main structure of the municipal tunnel and its waterproof measures are both summarized in this paper. Reinforced concrete frame structure with one story and three box-shaped sections is used in the design of the municipal tunnel. Both self-waterproof structure and waterproof sheet are applied to prevent ground water from permeating into the subaqueous tunnel. The installation of public cables and pipes are still elucidated in the paper. The typical structure of the municipal tunnel can be a guiding reference for the design of other subaqueous tunnel to cross urban rivers under analogous conditions.

Abstract: The steel-concrete joint section is a critical structure of load transmission in cable-stayed bridge girder. Under the requirement of calculation efficiency, correct numerical simulation is an important method to acquire the inter stress and deflection on the joint section of cable-stayed bridge girder. Taken the steel-concrete joint section finite element analysis of a cable-stayed bridge as an engineering background, the whole process simulation method of cable-stayed bridge steel-concrete joint section is introduced, which considering the nonlinear bond slippage effect and ANSYS program is employed. The effect on mechanical behavior and damage pattern of structures is also compared among different stud constitutive relation. The calculation results show that the numerical results of nonlinear stud joint section FE model are in a good agreement with the model experiment testing data. The equivalent stress of bearing plate from the simulation is relatively high under the ultimate load, and, the crack distribute at the whole concrete section. The calculation results of linear stud FE joint section model are close to the results of nonlinear stud joint section FE model under the design load. Under the ultimate load, the choice of different stud shear stiff model has effect on the concrete at crack initial moment. While after the most concrete crack, there is little difference on the crack distribution between the nonlinear and linear stud joint section FE model.

Abstract: The research integrates both phase change materials (PCM) and carbon nanotube (CNT)/carbon nanofiber (CNF) into cement mortars to improve their thermal and mechanical performances. The PCM will improve the thermal storage capability of the cement mortars, while CNT/CNF can improve their mechanical strength and thermal conductivity. Experimental results show that addition of 1 wt. % CNT and CNF into the cement mortars with 5 wt.% PCM can increase their compressive strength by 23% and 8% respectively, and increase their thermal conductivity by 26% and 9% respectively.