Advanced Materials Research Vols. 446-449

Abstract: Nowadays, the hollow floor is widely used due to its excellent mechanical property and economic benefit. However, its related specification is absence of evaluation in geometric parameters; furthermore, the research on the geometric parameters is seldom involved. This thesis has achieved automatic modeling, analysis and data processing concerning the hollow floor by python script. Based on ABAQUS secondary development and the statistical analysis software SPSS, single parameter analysis and the partial correlation between the parameters and the construction cost are carried out in this thesis. According to a number of case studies, the impact of every single parameter on the construction cost and the correlation of geometric parameters with construction cost were achieved. The above mentioned conclusions will be conducive to engineering design and further research in this field.

Abstract: Based on an engineering example,the FLAC-3D was applied to set up numerical analysis,analyzing the influence of the overloading acting position and the magnitude on the horizontal and vertical displacement of the foundation pit.Some useful conclusion was obtained,which will offer reference to the design and construction of the soil nailing.

Abstract: The uncertainty of long-term bonding strength of flue gas desulfurization building gypsum and cement based construction materials is the major issue impeding the application of flue gas desulfurization building gypsum in construction. A polymer cement mortar is suggested to get high bonding quality with flue gas desulfurization building gypsum. Long-term bonding observation has been carried out to verify the bonding performance of suggested polymer cement mortar with flue gas desulfurization gypsum. The results show that the bonding strength is up to 3.0MPa, and the bonding between them is durable.

Abstract: Assurance of integrity of structures is the main task of structural health monitoring. The condition (health) of a structure may be revealed from its dynamic characteristics in response to natural or man-made loads. As the measurement of the natural or operating forces on actual real-life structures is generally formidable, dynamic characteristics of the structures have to be extracted from the available output signals only. The stochastic subspace identification (SSI) technique is adopted in this study to identify the equivalent system parameters of the discrete-time state equation using covariance functions of the measured output signals. With the system parameters realized, the method of damage locating vector (DLV) is then considered for further assessment. Members with nearly zero stress under the loadings of DLVs are considered potentially damaged, whereas the DLVs are derived from singular value decomposition of the change in flexibility matrix of the structure before and after the damage state. In this study, the feasibility of DLV method for damage detection of a planar structure is explored based on its seismic responses. To comply with the desired output-only scenario, the information of ground motion is discarded in the stage of SSI analysis. Despite the non-stationary nature of earthquakes, the proposed scheme has been proved sufficient for damage localization of structures from global responses (floor accelerations). The damaged locations can be identified when the structure is fully observed, regardless of single or multiple damages. In the case of partial but co-located observation (damaged floors observed), the damaged locations can still be identified with acceptable accuracy and reliability.

Abstract: Turbine composite regenerative damper is one of new type damper which can regenerate the energy of vibration. The component and principle of generator and regenerate energy for turbine composite regenerative damper is introduce, and based on hydrodynamics and axial turbine basic principle, the relationship between induced electromotive force and piston velocity ,load resistance is induced. At last, the relationship between damping force and piston velocity, load resistance is induced too. The method is meaningful to understand and instruct the design of turbine composite regenerative damper.

Abstract: In view of the large amounts of discarded sludge produced in the process of engineering construction, this paper proposes and makes use of the discarded sludge and compounds a kind of lightweight soil of adjustable intensity. In order to get the physical properties of the lightweight soil, a series of laboratory tests is made to investigate the lightweight EPS beads compounded soil using the sludge as raw material soil, cement as the solidification material, and the effect of cement content, EPS beads volume fraction and curing age, etc. on the density and strength is analyzed. The change regularity is obtained of the density and strength parameters of lightweight soil using recycled sludge with each factor. The research results can provide fundamental basis for the application and quality control of engineering waste soil, and can establish a theoretical foundation for further development and utilization.

Abstract: This paper analyze the principle of the soil pressure caused by the sustaining structures. The author divides the soil pressure into two parts: first part is generated by digging and unloading and the value is close to the static value; another part is generated by resisting soil force related to the displacement of the structure and the value is proportional to the displacement, and applied the horizontal bedding coefficient of the sectioned stable value. And based on the elastic mechanical theory, the author established the flexing formula of these structures and answered it. And at last, this paper proved the practicality of this solution by a certain foundation test.

Abstract: The impact of stirrup corrosion on the constraint of corroded reinforced concrete(CRC) column is an pressing problem that needs to be solved. In this paper, 12 corroded CRC short-columns and 3 uncorroded CRC short-columns with dimension of 150mm×150mm×450mm have been prepared for the axial compression experiment. Through the experiment, the total cross-section stress-strain curves of the short-columns were measured under different degrees of stirrups corrosion, and the effects of corrosion rate of stirrups on the shape of the total cross-section stress-strain curves, bearing capacity, deformation and the mechanical parameters of confined concrete have been investigated. According to the results, the corrosion of stirrups has reduced their section, changed the material quality and damaged the concrete cover, which reduces the constraint to the core concrete; the shape changes of stress-strain curve illustrate that the destructive form of short-columns developed form ductility damage to brittle failure gradually.

Abstract: Based on six basic assumptions and deformation behaviour, the total potential energy of arches are obtained. The basic displacement functions are expressed with spline function. According to minmum potential energy principle, the characteristic equation is deducted. The characteristic value is solved by multiplication power method. An exampleof arches in the action of endmoment is calculated. The critical positive and negtive moment of out-of-plane stability in arches with single sysmetry axis section are studied.

Abstract: The ABAQUS finite element software is used to calculate the vertical bearing capacity of single piles in Tianjin, and the finite element results are compared with the data gained through the in-situ static load pile foundation tests. It is found that the Young’s modulus of the soil at the bottom of the pile could have a important role in improving the vertical bearing capacity of single piles.