scholarly journals Experimental Study on Distribution of Landslide Thrust in Pile-Anchor Structure based on Photoelastic Technique

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1358
Author(s):  
Xunchang Li ◽  
Rui Xu ◽  
Wei Yang ◽  
Pingan Li ◽  
Ke Yang ◽  
...  

This paper aimed to perform systematical study on the distribution of landslide thrust in pile-anchor support system, which has been a widely applicable treatment method in landslide control with safety, highly efficiency and adaptation. The advantage of photoelastic technique is visualization of strain and stress fields, therefore photoelastic model tests are conducted to show the distribution of landslide thrust in pile-anchor structure before failure in landslide. The effects of different materials and pile lengths are investigated by 6 photoelastic test cases under different loading conditions. It can be found from quantitative analysis of experimental results that load proportion of anchor would increase gradually with the decrease of pile embedded depth or the increase of landslide thrust force. Meanwhile, landslide thrust distribution in pile-anchor structure is directly affected by the stiffness of piles. The pile-anchor structure is significantly better at reducing bending moment value and optimizing bending moment distribution of pile. Finally, some theoretical analysis and design suggestions are proposed based on the experimental study.

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Ming-yi Zhang ◽  
Jia-xiao Ma ◽  
Shu-juan Yang ◽  
Yong-hong Wang ◽  
Xiao-yu Bai ◽  
...  

Double-row steel pipe piles have been widely used in retaining and protection of foundation excavation because of the advantages of high bearing capacity, high flexural rigidity, fast construction speed, and so on. This study presents a field test to assess the feasibility of strain gauges in monitoring the strain of double-row steel pipe piles during foundation excavation. Two steel pipe piles were instrumented with strain gauges and then installed into the drilling holes. The installation method of strain gauges is introduced first. Then, the bending moment of the test piles during the foundation excavation was analyzed. The field test results indicate that the survival rate of strain gauges was 100%, and the monitoring method used in the test was feasible to measure the bending moment of double-row steel pipe piles. Moreover, with the increase in foundation excavation depth, the bending moment of the test piles all increased, and the bending moment of the inner pile was obviously higher than that of the outer pile. The bending moment distribution of the whole support system accords with the conventional pile-anchor mode. The test results can provide reference and basis for the design and construction of double-row steel pipe piles.


Author(s):  
Crisbin Joseph Mathew

Abstract: Due to the rise in population and increase in urbanisation levels in our country, most of the settlements are in urban areas. As the cities that already existing are heavily populated along with a great deal of limitations in the infrastructure, emergence of an advanced township away from the vicinity of these overpopulated urban areas offer safer and better accommodation for the people. The planning and layout of the project is shown using autoCAD and for the structural analysis we use STADD Pro V.18i. Demographic analysis is done among specific clientele. Development of roof top rainwater harvesting(sump)has been carried out in order to provide source of water for the whole population of the township. Use of intze tank which is a circular overhead tank to meet the daily water requirement of the population inside the township.For the proper disposal and processing of the waste generated, almost 30 acres of land is being used to hold the per capita waste generated which managed after calculating factors like total waste generated, estimated landfill, total area required for land etc. The salient features a major advantages of this township is discussed in detail. Keywords: IS - Indian Standard BM - Bending Moment BIS - Bureau of Indian Standards cm - CentiMeters mm - MilliMeters m - Meter C - Celsius


2008 ◽  
Vol 20 (5) ◽  
pp. 650-655 ◽  
Author(s):  
Wen Cheng ◽  
Wen-hong Liu ◽  
Bao-wei Hu ◽  
Tian Wan

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6131
Author(s):  
Mamun Abu-Tair ◽  
Soufiene Djahel ◽  
Philip Perry ◽  
Bryan Scotney ◽  
Unsub Zia ◽  
...  

Internet of Things (IoT) technology is increasingly pervasive in all aspects of our life and its usage is anticipated to significantly increase in future Smart Cities to support their myriad of revolutionary applications. This paper introduces a new architecture that can support several IoT-enabled smart home use cases, with a specified level of security and privacy preservation. The security threats that may target such an architecture are highlighted along with the cryptographic algorithms that can prevent them. An experimental study is performed to provide more insights about the suitability of several lightweight cryptographic algorithms for use in securing the constrained IoT devices used in the proposed architecture. The obtained results showed that many modern lightweight symmetric cryptography algorithms, as CLEFIA and TRIVIUM, are optimized for hardware implementations and can consume up to 10 times more energy than the legacy techniques when they are implemented in software. Moreover, the experiments results highlight that CLEFIA significantly outperforms TRIVIUM under all of the investigated test cases, and the latter performs 100 times worse than the legacy cryptographic algorithms tested.


2010 ◽  
Vol 163-167 ◽  
pp. 1236-1240
Author(s):  
Xuan Sheng Cheng ◽  
Zhi Zhou

Reinforced concrete is the current main material to build liquid-storage structure. Because coarse aggregate and fine aggregate have different expansion coefficient under thermal environment, the expansion crack and leakage will happen. it will make liquid-storage structure failure. So thermal effect has become the most important factor that can not be ignored in the structure analysis and design. In this paper, adopting FEM software ANSYS, considering four-cell reinforced concrete rectangular liquid-storage structure at different temperature, heat-solid coupling numerical simulation analysis is proceeded, and the axial (shear) force and bending moment distribution are obtained.


Author(s):  
Zhao Wang ◽  
Wei Qin ◽  
Xiaojie Zhang ◽  
Jiannan Zhao ◽  
Yong Bai

Abstract The steel lazy wave riser has been used in deep-water oil and gas field development because it has good adaption to the movement of the upper platform and economic efficiency. The typical design criterion and design flow of steel lazy wave riser are introduced in this paper. The design method and the equivalence principle of distributed buoyancy modules are given. The formulas of equivalent hydrodynamic parameters are derived in this paper. The influences of distributed buoyancy modules (DBM) and the buoyancy factor on the configuration of the riser, the top tension, and the bending moment distribution are discussed and summarized. The distribution law of effective stress response along the pipe can be analyzed by dynamic analysis, and it provides reference for the global design of steel lazy wave riser.


Author(s):  
Xing Zheng ◽  
Toshiyuki Sawa ◽  
Mei Feng ◽  
Honggui Ding

Abstract After a bolted gasketed pipe flange connection is assembled, the pipe flange connection is usually subjected to some additional loads such as bending moment, own weight, wind load and so on. These additional loads will lead to changing the axial bolt force distribution of the pipe flange connection and the distribution will become more and more scattered. As a result, the minimum residual axial bolt force will be much smaller and the minimum contact gasket stress will decrease, so a leakage is easy to occur in the connection. In special cases such as earthquakes, the bolted pipe flange connection is usually subjected to a high bending moment. Then sometimes leakage accidents occur. In order to promote the safety of the connections and to avoid them being broken under the earthquakes, in the present paper, the equivalent pressure and the assembly efficiency in the pipe flange connection of class 150 4″ are measured experimentally. The leak rates of the connection using spiral-wound gasket when a bending moment was applied or not applied were measured to elicit the equivalent pressure. Moreover, some tightening procedures such as JIS B 2251, ASME PCC-1 Legacy and GB/T 38343 were applied to tighten the pipe flange connection. The axial bolt force distribution, the assembly efficiency based on the target axial bolt force and the assembly efficiency based on tightness parameter of the connection when bending moment was applied or not applied were measured, and the results are compared. As a result, the equivalent pressure under a given bending moment is obtained, and a difference of the equivalent pressure between our results and Kellogg’s results is demonstrated. In addition, the new assembly efficiency based on the tightness parameter is also measured under a given bending moment as well as internal pressure. Using the equivalent pressure and the assembly efficiency obtained in the present paper, a new design will be possible for pipe flange connections under bending moment.


Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2949
Author(s):  
Florin Dumbrava ◽  
Camelia Cerbu

The aspects regarding the stiffness of the connections between the beams that support the storage pallets and the uprights is very important in the analysis of the displacements and stresses in the storage racking systems. The main purpose of this paper is to study the effects of both upright thickness and tab connector type on the rotational stiffness and on the capable bending moment of the connection. For this purpose, a number of 18 different groups of beam-connector-upright assemblies are prepared by combining three types of beams (different sizes of the box cross section), three kinds of uprights profiles (with a different thickness of the section walls), and two types of connectors (four-tab connectors and five-tab connectors). Flexural tests were carried out on 101 assemblies. For the assemblies containing the uprights having the thickness of 1.5 mm, the five-tab connector leads to a higher value of the capable moment and higher rotational stiffness than similar assemblies with four-tab connectors. A contrary phenomenon happens in case of the assemblies containing the upright profiles having a thickness of 2.0 mm regarding the capable design moment. It is shown how the safety coefficient of connection depends on both the rotational stiffness and capable bending moment.


2010 ◽  
Vol 10 (03) ◽  
pp. 387-409 ◽  
Author(s):  
JOSÉ R. IBAÑEZ ◽  
MIGUEL A. SERNA

The assessment of the design buckling resistance of single members is usually based either directly on the elastic buckling resistance of the member or indirectly on its non-dimensional slenderness computed from the elastic buckling resistance. Specifically, Eurocode 3 buckling curves define the buckling reduction factors as a function of non-dimensional slenderness and, according to EC3 "General Method", these curves may also be used for non-uniform members. In this context, a new procedure will be presented for the computation of the elastic critical moment of tapered members. As is well known, the elastic critical moment strongly depends on both the bending moment diagram and end support restrictions. For uniform members, elastic critical moments may be computed using a relatively simple formula in which the bending moment distribution is taken into account by an equivalent uniform moment factor, and the end support restrictions are introduced through the buckling length. Unfortunately, this formula has not been extended to tapered members and, as a consequence, the elastic critical moment for tapered beams must be obtained using numerical methods such as the finite element methods. Based on a comprehensive parametric study for the elastic critical moment of tapered beams with different moment diagrams, this paper offers a new procedure, called the Equivalent Moment Approach, for the substitution of a tapered beam with any moment diagram by an equivalent uniform beam. One advantage of the present procedure is that closed form expressions valid for uniform beam can be generalized and used for tapered beams.


1982 ◽  
Vol 104 (4) ◽  
pp. 313-318 ◽  
Author(s):  
N. Suzuki ◽  
N. Jingu

Theoretical and experimental study on dynamic behavior of submarine pipelines under laying operation with articulated stingers is described in this paper. Wave response tests in regular waves and forced oscillation tests in still water were conducted using the 1/20 scale model of 406.4 mm o.d. (16 in. o.d.) pipeline laid in 150 m (500 ft) water depth. The results show that: 1) the maximum dynamic bending moment of pipeline MDmax occur at a stinger roller, 2) dynamic bending moment of pipelines MD at shorter periods are larger than those at longer periods, 3) the values of MD in an over-bend region depend highly upon stinger motion, 4) those of MD in a sag-bend region are less than MD max in an over-bend region, 5) the values of MD/HMY increase as the stinger volume increases and that 6) stinger motion at shorter periods are different from those at longer periods.


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