Model Test and Application Research of Micro-Pile on Landslide Control

2014 ◽  
Vol 522-524 ◽  
pp. 141-146
Author(s):  
Sheng Li Tang ◽  
Le Zhou ◽  
Bei Bei Han

It is a new trend to control landslide by using anti-sliding composite structure of micro-piles combined with other engineering measures. At present, it is extensively applied to engineering practice for convenient construction, low cost, grouting pressure enhances the stability of landslide strikingly etc. Based on the analysis of the mechanism anti-sliding of micro-pile, characteristics of micro-piles under horizontal supporting force are studied by modest test. Finally, checking the sheer stability of micro-pile and combining with engineering example proves the feasibility and reliability of micro-pile on landslide control.

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Yichen Miao ◽  
Baoxian Liu ◽  
Changwu Liu ◽  
Zhile Shu ◽  
Haikuan Wu

In order to create more underground space, it was important to investigate the impact of excavation on the preexisting building. In this paper, a scale model test was conducted to analyze the stability of the structure during excavation. The model consisted of underpinning piles preinstalled in clay, with a reinforced concrete building placed on underpinning piles. The strain and settlement of the structure were observed to reveal the time settlement of columns and the time strain of beams, columns, and piles during excavation. The results showed that the strain change of beams was small, and strain values of columns were getting higher. And underpinning piles had great strain variations. They were of great significance to underpinning design and engineering practice.


2012 ◽  
Vol 204-208 ◽  
pp. 1673-1677
Author(s):  
Sheng Li Tang ◽  
Le Zhou ◽  
Zhang Wu ◽  
Xiao Long Dang

It is a new trend to control landslide by using anti-sliding composite structure of micro-piles combined with other engineering measures. It has been applied in many engineer practices for its convenient, less cost, and high landslide stability increased obviously by the pressure grouting. The paper discussed formation lithology, geologic structure and hydrogeology features of Xining-Jiuzhi highway as an example, according to the specific circumstance of sliding zones in superficial layer and deep layer, we proposed a comprehensive landslide treatment, combined with anti-sliding composite structure of micro-piles, anchor cable frame reinforcing and inclined drain holes. On the basis of analyzing the effect and theory of consolidating the slide by anti-sliding composite structure of micro-piles, we adopted the numerical model of lagrange finite-difference analyzing the stability of landslides and the load-carrying properties of the reinforced structure before and afterwards comparatively. The calculated results and monitoring showed that: the landslides were stable, and the comprehensive treatment of using anti-sliding composite structure of micro-piles has met the expectant control effects.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1282
Author(s):  
Ioannis Deretzis ◽  
Corrado Bongiorno ◽  
Giovanni Mannino ◽  
Emanuele Smecca ◽  
Salvatore Sanzaro ◽  
...  

The realization of stable inorganic perovskites is crucial to enable low-cost solution-processed photovoltaics. However, the main candidate material, CsPbI3, suffers from a spontaneous phase transition at room temperature towards a photo-inactive orthorhombic δ-phase (yellow phase). Here we used theoretical and experimental methods to study the structural and electronic features that determine the stability of the CsPbI3 perovskite. We argued that the two physical characteristics that favor the black perovskite phase at low temperatures are the strong spatial confinement in nanocrystalline structures and the level of electron doping in the material. Within this context, we discussed practical procedures for the realization of long-lasting inorganic lead halide perovskites.


2021 ◽  
Vol 2 (2) ◽  
pp. 325-334
Author(s):  
Neda Javadi ◽  
Hamed Khodadadi Tirkolaei ◽  
Nasser Hamdan ◽  
Edward Kavazanjian

The stability (longevity of activity) of three crude urease extracts was evaluated in a laboratory study as part of an effort to reduce the cost of urease for applications that do not require high purity enzyme. A low-cost, stable source of urease will greatly facilitate engineering applications of urease such as biocementation of soil. Inexpensive crude extracts of urease have been shown to be effective at hydrolyzing urea for carbonate precipitation. However, some studies have suggested that the activity of a crude extract may decrease with time, limiting the potential for its mass production for commercial applications. The stability of crude urease extracts shown to be effective for biocementation was studied. The crude extracts were obtained from jack beans via a simple extraction process, stored at room temperature and at 4 ℃, and periodically tested to evaluate their stability. To facilitate storage and transportation of the extracted enzyme, the longevity of the enzyme following freeze drying (lyophilization) to reduce the crude extract to a powder and subsequent re-hydration into an aqueous solution was evaluated. In an attempt to improve the shelf life of the lyophilized extract, dextran and sucrose were added during lyophilization. The stability of purified commercial urease following rehydration was also investigated. Results of the laboratory tests showed that the lyophilized crude extract maintained its activity during storage more effectively than either the crude extract solution or the rehydrated commercial urease. While incorporating 2% dextran (w/v) prior to lyophilization of the crude extract increased the overall enzymatic activity, it did not enhance the stability of the urease during storage.


Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4166
Author(s):  
Román Fernández ◽  
María Calero ◽  
Yolanda Jiménez ◽  
Antonio Arnau

Monolithic quartz crystal microbalance (MQCM) has recently emerged as a very promising technology suitable for biosensing applications. These devices consist of an array of miniaturized QCM sensors integrated within the same quartz substrate capable of detecting multiple target analytes simultaneously. Their relevant benefits include high throughput, low cost per sensor unit, low sample/reagent consumption and fast sensing response. Despite the great potential of MQCM, unwanted environmental factors (e.g., temperature, humidity, vibrations, or pressure) and perturbations intrinsic to the sensor setup (e.g., mechanical stress exerted by the measurement cell or electronic noise of the characterization system) can affect sensor stability, masking the signal of interest and degrading the limit of detection (LoD). Here, we present a method based on the discrete wavelet transform (DWT) to improve the stability of the resonance frequency and dissipation signals in real time. The method takes advantage of the similarity among the noise patterns of the resonators integrated in an MQCM device to mitigate disturbing factors that impact on sensor response. Performance of the method is validated by studying the adsorption of proteins (neutravidin and biotinylated albumin) under external controlled factors (temperature and pressure/flow rate) that simulate unwanted disturbances.


2016 ◽  
Vol 08 (07) ◽  
pp. 1640009 ◽  
Author(s):  
Fengfeng Li ◽  
Liwu Liu ◽  
Xin Lan ◽  
Tong Wang ◽  
Xiangyu Li ◽  
...  

With large spatial deployable antennas used more widely, the stability of deployable antennas is attracting more attention. The form of the support structure is an important factor of the antenna’s natural frequency, which is essential to study to prevent the resonance. The deployable truss structures based on shape memory polymer composites (SMPCs) have made themselves feasible for their unique properties such as highly reliable, low-cost, light weight, and self-deployment without complex mechanical devices compared with conventional deployable masts. This study offers deliverables as follows: an establishment of three-longeron beam and three-longeron truss finite element models by using ABAQUS; calculation of natural frequencies and vibration modes; parameter studies for influence on their dynamic properties; manufacture of a three-longeron truss based on SMPC, and modal test of the three-longeron truss. The results show that modal test and finite element simulation fit well.


2013 ◽  
Vol 846-847 ◽  
pp. 190-194
Author(s):  
Shu Jun Yin ◽  
Xue Ren Li ◽  
Ji Geng Luo

The paper designs a three-phase high voltage power supply system based on active disturbance rejection controller which make single-chip microcomputer ATmega128 as the main control chip and the system improve the stability and control precision of dust removing power. Engineering practice shows that, the DC power supply system has the advantages of convenient operation, high work efficiency, system stability.


2021 ◽  
pp. 100
Author(s):  
chensheng wang

The color revolution, which is a “low-cost and high-return” method in regime change, has become the main mean and priority option for America to subvert dissident regimes. In recent years, with the raising strength of containing and suppressing between China with Russia by the United States, America has tried its best to plan “color revolution” not only around China and Russia, but also within the borders of the two countries. China and Russia have become the key target of America in implementing the “color revolution”, however, the situation of the two countries to prevent the “color revolution” is particularly urgent. The “color revolution” not only disrupts the balance of the international system and regional security, but also seriously affects the stability of the country's political power and the healthy development of the economy. In view of this, it is now necessary for China and Russia to work together to prevent “color revolution”. Regarding the new changes, methods changed from non-violent to violent me, more advanced organizational methods, the younger generation of the participants, and changes in manifestations by the “color revolution”, as well as the underlying causes of the “color revolution”, China and Russia should have uindividualized strategies. China and Russia can strengthen cooperation in different areas, such as politics, economy, culture, ideological education, and regional coordination. China and Russia should take advantages of their respective experiences in dealing with “color revolution”, strengthen sharing and communicating experience with other countries in the region, and jointly build a barrier to prevent “color revolution” and protect the security and stability in China and Russia and the surrounding areas.


2021 ◽  
Author(s):  
Tan Li ◽  
Guangbo Chen ◽  
Zhongcheng Qin ◽  
Qinghai Li

Abstract The stability of coal-rock composite structures is of great significance to coal mine safety production. To study the stability and deformation failure characteristics of the coal-rock composite structure, the uniaxial cyclic loading tests of the coal-rock composite structures with different coal-rock height ratios were carried out. Lithology and coal-rock height ratio play an important role in the energy dissipation of coal-rock composite structures. The higher the coal-rock height ratio, the greater the average elastic energy and dissipated energy produced per cycle of coal-rock composite structures, the smaller the total elastic energy and dissipated energy produced in the process of cyclic loading. Based on the difference of damage variables calculated by dissipative energy method and acoustic emission method, a more sensitive joint calculation method for calculating damage variable was proposed. The joint damage variable calculation method can more accurately and sensitively reflect the damage of coal-rock composite structure under cyclic loading. The macroscopic crack first appears in the coal specimen in the coal-rock composite structure, the degree of broken coal specimens in the composite structure is inversely proportional to the coal-rock height ratio. The strength and deformation characteristics of the coal-rock composite structure are mainly affected by coal sample in the composite structure.


1991 ◽  
Author(s):  
Barry Deakin

During the development of new stability regulations for the U.K. Department of Transport, doubt was cast over many of the assumptions made when assessing the stability of sailing vessels. In order to investigate the traditional methods a programme of work was undertaken including wind tunnel tests and full scale data acquisition. The work resulted in a much improved understanding of the behaviour of sailing vessels and indeed indicated that the conventional methods of stability assessment are invalid, the rules now applied in the U.K. being very different to those in use elsewhere. The paper concentrates on the model test techniques which were developed specifically for this project but which will have implications to other vessel types. The tests were of two kinds: measurement of the wind forces and moments on a sailing vessel; and investigation of the response of sailing vessels to gusts of wind. For the force and moment measurements models were mounted in a tank of water on a six component balance and tested in a large boundary layer wind tunnel. Previous tests in wind tunnels have always concentrated on performance and the heeling moments have not normally been measured correctly. As the measurements of heeling moment at a range of heel angles was of prime importance a new balance and mounting system was developed which enabled the above water part of the vessel to be modelled correctly, the underwater part to be unaffected by the wind, and the interface to be correctly represented without interference. Various effects were investigated including rig type, sheeting, heading, heel angle and wind gradient. The gust response tests were conducted with Froude scaled models floating in a pond set in the wind tunnel floor. A mechanism was installed in the tunnel which enabled gusts of various characteristics to be generated, and the roll response of the models was measured with a gyroscope. These tests provided information on the effects of inertia, damping, rolling and the characteristics of the gust. Sample results are presented to illustrate the uses to which these techniques have been put.


Sign in / Sign up

Export Citation Format

Share Document