Study the Impact of Differential Settlement on Frame Structure through Back-Analysis Method

2013 ◽  
Vol 671-674 ◽  
pp. 799-803
Author(s):  
Nan Jiang ◽  
Li Ming Huang
Keyword(s):  
Three Dimensional ◽  
Back Analysis ◽  
Bending Moment ◽  
Measured Data ◽  
Differential Settlement ◽  
Frame Structure ◽  
Analysis Method ◽  
Piled Raft Foundation ◽  
The Impact ◽  
Pile Length

This paper studied the impact of differential settlement of foundation on the inner force of architectural structure by applying back-analysis method. By taking the three-dimensional coactions system of upper structure-piled raft foundation-foundation with different pile length and different raft thickness as the research object, its differential settlement law of foundation under the effect of load was studied, which was combined with the practical measured data to fit the quadratic settlement surface equation of the foundation. The analysis demonstrated that the differential settlement of foundation will change the inner force of upper structure significantly, thus enabling most of construction components to produce great additional axial force, additional shearing force and additional bending moment, especially changing the additional inner force of corner post more evidently.

Numerical Analysis on Interaction of Superstructure-Piled Raft Foundation-Foundation Soil

2011 ◽  
Vol 261-263 ◽  
pp. 1578-1583
Author(s):  
Yong Le Li ◽  
Jiang Feng Wang ◽  
Qian Wang ◽  
Kun Yang
Keyword(s):  
Design Method ◽  
Bending Moment ◽  
Load Sharing ◽  
Differential Settlement ◽  
Pile Head ◽  
Secondary Stress ◽  
Foundation Soil ◽  
Piled Raft Foundation ◽  
Raft Foundation ◽  
Soil Load

based on the finite element method of superstructure-the pile raft foundation-the foundation soil action and interaction are studied. Research shows that the common function is considered, fundamental overall settlement and differential settlement with the increase of floor of a nonlinear trend. The influence of superstructure form is bigger for raft stress, the upper structure existing in secondary stress, and the bending moment and axial force than conventional design method slants big; With the increase of the floors, pile load sharing ratio is reduced gradually,but soil load sharing ratio is increased. Along with the increase of the upper structure stiffness, the load focused on corner and side pile; Increasing thickness of raft, can reduce the certain differential settlement and foundation average settlement, thus reducing the upper structure of secondary stress and improving of foundation soil load sharing ratio, at the same time the distribution of counterforce on the pile head is more uneven under raft, thus requiring more uneven from raft stress, considering the piles under raft and the stress of soils to comprehensive determines a reasonable raft thickness, which makes the design safety economy. As the foundation soil modulus of deformation of foundation soil improvement, sharing the upper loads increases, counterforce on the pile head incline to average, raft maximum bending moment decrease gradually.

Numerical Simulation of Inclined Multi-Seam Mining Subsidence of Considered the Impact by Faults

2011 ◽  
Vol 250-253 ◽  
pp. 2135-2140
Author(s):  
Zhi Ping Wu ◽  
Sheng Hua Qiu ◽  
Ying Li
Keyword(s):  
Working Conditions ◽  
Three Dimensional ◽  
Surface Subsidence ◽  
Differential Settlement ◽  
Geological Condition ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Seam Mining ◽  
The Impact ◽  
Roof Strata

According to the complex mining geological condition of Shandong gentle inclined multi-seam mining, Use the three-dimensional finite element numerical analysis software to establish three-dimensional geological model under the different mining working conditions. Taking into account the impact of faults to calculate multi-seam roof strata movement and surface subsidence caused by the different mining working conditions. The level displacement & subsidence distribution curve of the reference point of surface & multi-seam roof strata under the different working conditions is shown. The maximum, minimum settlement, differential settlement and subsidence diagram is shown. And the principal stress, shear stress value of surface & multi-seam roof strata after mining also is shown. The results showed that: little change of the biggest surface subsidence and differential settlement is caused by mining 3101&3102 face or separate 3101 or 3102 face. And the largest subsidence, and the settlement difference of the surface is 520mm, 498mm, 515mm and 59mm, 78mm, 81mm, Respectively. It provides an reference for reasonable, safe, economic for the inclined multi-seam mining under similar conditions.

Impact compression behaviors of high-capacity long piles

2010 ◽  
Vol 47 (12) ◽  
pp. 1335-1350 ◽  
Author(s):  
Arthur K.O. So ◽  
Charles W.W. Ng
Keyword(s):  
Energy Transfer ◽  
Impact Velocity ◽  
Stress Wave ◽  
Impact Energy ◽  
High Capacity ◽  
Measured Data ◽  
Impact Compression ◽  
Impact Forces ◽  
The Impact ◽  
Pile Length

The Hiley formula underestimates driving resistance of long piles. Methods using affected pile length have been suggested, but have been found to be inapplicable for high-capacity piles. The impact compression behaviors of about 4700 high-capacity H-piles that were 14–80 m long at final set were studied. Measured data revealed that maximum impact forces are very scattered, but their means are independent of the hammer type, ram weight, ram drop, impact velocity, and pile length. Maximum impact compression of pile and affected pile length exist in both long and short piles. The affected pile length in turn is significant to the blow efficiency, hammer constant, and energy transfer ratio. This length is governed by the impact momentum and impact energy, and can be estimated by an energy-based equation. If the affected pile length determined by this equation is substituted into the Hiley formula to back-analyze the driving resistance, predictability of the driving formula can be improved by about 8%. This improvement is significant enough to reduce the number of hammer blows required at very hard driving conditions and reduce pile damage. Furthermore, this proposed equation is simple to use in the field and is more economical compared with stress-wave monitoring techniques.

scholarly journals X-ray Computed Tomography Method for Macroscopic Structural Property Evaluation of Active Twist Composite Blades

Aerospace ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 370
Author(s):  
Joon H. Ahn ◽  
Hyun J. Hwang ◽  
Sehoon Chang ◽  
Sung Nam Jung ◽  
Steffen Kalow ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Structural Properties ◽  
Digital Image ◽  
Torsional Rigidity ◽  
Three Dimensional ◽  
Measured Data ◽  
X Ray ◽  
X Ray Computed ◽  
Active Twist ◽  
The Impact

This paper describes an evaluation of the structural properties of the next-generation active twist blade using X-ray computed tomography (CT) combined with digital image processing. This non-destructive testing technique avoids the costly demolition of the blade structure. The CT scan covers the whole blade region, including the root, transition, and tip regions, as well as the airfoil blade regions, in which there are spanwise variations in the interior structural layout due to the existence of heavy instrumentation. The three-dimensional digital image data are processed at selected radial stations, and finite element beam cross-section analyses are conducted to evaluate the structural properties of the blade at the macroscopic level. The fidelity of the digital blade model is first assessed by correlating the estimated blade mass with the measured data. A separate mechanical measurement is then carried out to determine the representative elastic properties of the blade and to verify the predicted results. The agreement is found to be good to excellent for the mass, elastic axis, flap bending, and torsional rigidity. The discrepancies are less than 2.0% for the mass and elastic axis locations, and about 8.1% for the blade stiffness properties, as compared with the measured data. Finally, a sensitivity analysis is conducted to clarify the impact of modeling the sensor and actuator cables, nose weight, and manufacturing imperfections on the structural properties of the blade.

A quasi-Monte Carlo statistical three-dimensional tolerance analysis method of products based on edge sampling

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chuanyuan Zhou ◽  
Zhenyu Liu ◽  
Chan Qiu ◽  
Jianrong Tan
Keyword(s):  
Monte Carlo ◽  
Three Dimensional ◽  
Sampling Strategy ◽  
Tolerance Analysis ◽  
Analysis Method ◽  
Content Type ◽  
Dimensional Tolerance ◽  
Quasi Monte Carlo ◽  
Edge Sampling ◽  
The Impact

Purpose The conventional statistical method of three-dimensional tolerance analysis requires numerous pseudo-random numbers and consumes enormous computations to increase the calculation accuracy, such as the Monte Carlo simulation. The purpose of this paper is to propose a novel method to overcome the problems. Design/methodology/approach With the combination of the quasi-Monte Carlo method and the unified Jacobian-torsor model, this paper proposes a three-dimensional tolerance analysis method based on edge sampling. By setting reasonable evaluation criteria, the sequence numbers representing relatively smaller deviations are excluded and the remaining numbers are selected and kept which represent deviations approximate to and still comply with the tolerance requirements. Findings The case study illustrates the effectiveness and superiority of the proposed method in that it can reduce the sample size, diminish the computations, predict wider tolerance ranges and improve the accuracy of three-dimensional tolerance of precision assembly simultaneously. Research limitations/implications The proposed method may be applied only when the dimensional and geometric tolerances are interpreted in the three-dimensional tolerance representation model. Practical implications The proposed tolerance analysis method can evaluate the impact of manufacturing errors on the product structure quantitatively and provide a theoretical basis for structural design, process planning and manufacture inspection. Originality/value The paper is original in proposing edge sampling as a sampling strategy to generating deviation numbers in tolerance analysis.

Numerical Simulation for Progressive Collapse and Protection of a Multi-Storey Building due to an Explosion in its Basement

2012 ◽  
Vol 226-228 ◽  
pp. 1034-1038 ◽  
Author(s):  
Li Tian ◽  
Zai Long Li
Keyword(s):  
Protective Effect ◽  
Aluminum Foam ◽  
Progressive Collapse ◽  
Three Dimensional ◽  
Protective Layer ◽  
Simulation Method ◽  
Coupling Model ◽  
Frame Structure ◽  
Load Path ◽  
The Impact

The progressive collapse of a multi-story building and its protective effect with aluminum foam under an explosion in its basement are numerically investigated in this paper. The three-dimensional coupling model composed of a multi-story frame structure with a basement and the surround soil is modeled using ANSYS/LS-DYNA. The progressive collapse of the entire structure under explosive impact and the protective effect of the aluminum foam are simulated using the proposed three-stage simulation method (TSSM). The result shows that, the aluminum foam as a protective layer can reduce the impact effects very well, and then can prevent progressive collapse effectively. The same model is also simulated by direct simulation method (DSM) and alternative load path method (ALPM). By comparison with the two methods, the TSSM is illustrated practical, accurate and economic for the analysis of progressive collapse.

Concrete Curved Box Girders Interacted with Vehicles in Braking or Acceleration

2018 ◽  
Vol 18 (04) ◽  
pp. 1850053 ◽  
Author(s):  
Xinyi Huang ◽  
Chung C. Fu ◽  
Weidong Zhuo ◽  
Quanzhe Yan ◽  
Ying Sun
Keyword(s):  
Spatial Analysis ◽  
Bending Moment ◽  
Considerable Effect ◽  
Dynamic Responses ◽  
Impact Factors ◽  
Analysis Method ◽  
Box Girders ◽  
Girder Bridge ◽  
Spatial Analysis Method ◽  
The Impact

In this study, an experimentally validated spatial analysis method for the vehicle–bridge interaction system was modified to include the features of vehicle braking and accelerating. The effect of braking or accelerating was considered as external force acting on the vehicular center of gravity and was quasi-statically distributed to every tandem, for which the formulae of load redistribution were derived. The effect of centrifugal force was also incorporated in the model. Based on the modified spatial analysis method, the dynamic responses of a three-span continuous concrete box girder bridge due to vehicle braking and accelerating were studied. Impact factors, including deflection, bending moment, torsional moment and shear force, were examined. The results show that vehicle braking has considerable effect on dynamic responses and the impact factors are related to braking rise time and braking position, but cases of vehicle braking do not always cause larger effects. While the increase in initial speed can produce higher maximum dynamic responses and corresponding impact factors, the dynamic responses in the first span of a multi-span bridge are smaller than those in other spans due to vehicle accelerating.

scholarly journals Foundation resistance analysis of Cisomang Bridge

2019 ◽  
Vol 270 ◽  
pp. 02003
Author(s):  
Kaisha Tamara ◽  
Tommy Ilyas
Keyword(s):  
Shear Strength ◽  
Research And Development ◽  
Slip Surface ◽  
Lateral Displacement ◽  
Back Analysis ◽  
Analysis Method ◽  
The Road ◽  
Total Displacement ◽  
Bore Pile ◽  
The Impact

Cisomang bridge is one of the bridges connecting Jakarta and Bandung through Cikampek-Padalarang (Cipularang) Highway. The Road and Bridge's Research and Development Centre (PUSJATAN) presents data that on December 23rd, 2016 Pier P2 of Cipularang Highway is shifted for 57,02 cm. This movement is suspected occurred due to decreasing of clayshale's shear strength caused by Cisomang River's seepage. Pier P2 movement is indicating lateral displacement of Cisomang Bridges foundation for 22 m deep which dominates the total displacement when compared to its settlement. Accordingly, we study trough back analysis method for determining the impact of bore pile reinforcement to lateral displacement on clayshale using PLAXIS to simulate the behaviour of soil. This research proposes 35 m and 60 m depth bore pile to be a foundation reinforcement. Aside from its contribution on decreasing lateral displacement of existing foundation up to 33-68%, this reinforcement cuts the slip surface of Cipularang slope and increases its safety factor (SF) for 4,7-16%.

Simulation Experimental Research for the Influence of Embedded Ratio on SMW’s Working Traits

2011 ◽  
Vol 250-253 ◽  
pp. 2322-2326
Author(s):  
Wen Zhao Chen ◽  
Quan Chen Gao ◽  
Jun She Jiang
Keyword(s):  
Soft Soil ◽  
Back Analysis ◽  
Bending Moment ◽  
Model Parameters ◽  
Foundation Pit ◽  
Action Effect ◽  
The Core ◽  
Variation Characteristics ◽  
Soil Foundation ◽  
The Impact

Through model test, the displacement of the top of the wall and the strain of the core pile with excavating were measured and the deformation and damage characteristics of the soft soil foundation pit supported bySMWwas revealed. By parameter sensitivity analysis and back analysis,ABAQUSwas applied to build the numerical simulation model ofSMWin soft soil and the model parameters were obtained and the model was optimized. The impact of the embedded depth on the displacement of the top of the wall ,strain of the core pile, the bending moment of the core pile and the surface subside were systematic studied. The curve fitting equations of the above mentioned action effect variables with embedded ratio were obtained. Studies have shown that embedded depth was significantly influenced the working properties ofSMW. When the embedded ratio reaches a critical value, the nonlinear variation characteristics of the above mentioned action effect variables will occur and the signs of foundation pit's failure will occur.

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