Drainage Plate Research Articles

A Case Study of Combined Drainage Consolidation‐Preloading Methods for a Highway Subgrade on Peat Soils

A highway project of up to 100 km/h is currently being constructed between Colombo and Katunayake International Airport across a Sri Lankan muskeg area. At this site, peat deposit was initially 0.8∼15.3 m thick and was underlain by sand, clay, or gneiss. The ground improvement methods adopted in the project were combined drainage consolidation‐preloading methods, pipe pile foundation, and geogrids. This paper provides a detailed insight into the implementation of combined drainage consolidation‐preloading methods used in the project, including sand pile, gravel pile, and plastic drainage plate as the prefabricated vertical drains. Periodical field‐level observations were taken during the ten years, including the construction and postconstruction periods. The results show that peat soils’ consolidation coefficient has been increased several times to tens of times due to ground improvement. After removing the temporary surcharge, the highway embankments did not heave and was followed by long‐term settlements totaling 1.3∼7.4 cm over the following seven years of observations. Analysis of the settlement records shows that combined drainage consolidation‐preloading methods have helped accelerate drainage consolidation and reduce postconstruction settlement.

Manipulator visual localization motion control for power cable mobile robot in dynamic-unstructured environment

PurposeTo improve the operational efficiency and intelligence of live operation robots in dynamic-unstructured operation environments, this paper aims to propose a fuzzy logic-based method for the autonomous search and visual localization control of a manipulator end effector applied to a drainage plate bolt on a high-voltage transmission line. The proposed approach is based on a four-way video image information output from a dual-operation manipulator.Design/methodology/approachFirst, based on the structural characteristics of the drainage line, an autonomous search method for the drainage plate bolt and a mapping relationship between the autonomous search control parameters and the relative posture of the operation manipulator-drainage line are proposed. The posture control parameters of the dual manipulators can then be obtained, and a two-dimensional fuzzy controller is designed with the posture offset distance and the posture offset angle as its input signals. This enables the localization control of the bolt and nut alignment to be realized through a visual process.FindingsThe proposed fuzzy control algorithm is used for bolt location control, and its performance is compared with that of the conventional approach. The simulation results indicate that the fuzzy control algorithm greatly improves the localization accuracy and operational efficiency of live operation robots.Originality/valueField operation experiments on actual transmission lines verify that the fuzzy control-based visual localization control of the robot manipulator has great engineering practicality. Therefore, the proposed method further improves operational intelligence compared with conventional algorithms.

Research on dual-arm coordination motion control strategy for power cable mobile robot

Regarding the typical operation tasks in high-voltage transmission line environment, in order to effectively eliminate or reduce the disadvantageous effects on the robot operation reliability caused by the close chain internal forces. According to the motion status of manipulator operation, the dual-arm coordination control of the mobile operation robot can be divided into three different modes, which are dual-arm independent operation mode, dual-arm fully constrained mode and dual-arm partially constrained mode. The dynamic model between dual-arm and operation objects for the three different models are established, respectively. The manipulator position and force are set as the control targets, a unified dual-arm coordination controller is designed for the three operation modes. Through the mutual compensation of force error and position error, the close chain internal force can be dynamically allocated in each joints, so that the robot joints force can be balanced during the operation, and the internal force in the close chain can be minimized during the operation process so as to ensure the operation reliability and safety. Finally, the validity and engineering practicability is verified by MATLAB simulation experiment and 220 kV living damper replacement and drainage plate bolt tightening operation experiment, respectively.

Composite Consolidation Coefficient Analysis of Soft Soil with Drainage Water

The consolidation coefficient is the most basic parameter to calculate the consolidation rate of soil layer, and the horizontal consolidation coefficient controls the radial water flow into the drainage well. Based on the background of the soft soil in Shantou, Guangdong Province, a series of experimental studies on the consolidation characteristics were carried out by using the modified consolidation instrument. And the concept of the composite consolidation coefficient of the drained water body was put forward. The composite consolidation coefficient reflects the consolidation characteristics of soft soil with drainage water, The test results showed that: 1) The consolidation test with drainage plate is basically consistent with the load compression curve, but its consolidation rate is fast, which is reflected by the composite consolidation coefficient. 2) In the consolidation test of water bodies with drainage, the vertical consolidation coefficient and radial consolidation coefficient are calculated by “three-point method”, and then the composite consolidation coefficient is obtained. The composite consolidation coefficient decreases with the increase of drain spacing ratio, effective drainage diameter and drainage height, which is basically consistent with the theoretical formula. 3) The vertical consolidation coefficient and radial consolidation coefficient decrease with the increase of the diameter of the sample, and the difference is obvious when the load is large. The large-size model with a diameter of 100 mm and a height of 100 mm is about 1.35 times of the vertical consolidation coefficient of the conventional consolidation test.

Research on energy saving improvement of ammonia desulphurization tower

All Coking chemical industry (also known as coking chemical industry) is a major component of the traditional coal chemical industry in China. In its production process will produce a large number of smokes containing SO2. In view of the above problems, the design of ammonia desulfurization tower has been improved in this paper. The pre-treatment step in the industry is completed in the desulfurization tower, and the baffle area is designed to separate the different reactions and collected the spray liquid, and a drainage plate is added at the flue gas inlet. The improved desulfurization tower can ensure the uniform distribution of flue gas inlet, but also can improve the absorption efficiency and increase the recycling of reagents.

Research on multifunctional automatic transmission line automatic robot system

In this paper, a special power industry robot suitable for live maintenance and repair of overhead transmission lines is studied. The robot meets the requirements of live working on transmission lines, which can autonomously climb up and down the transmission line and crawl along the lines. The robot has a variety of work function heads, which achieves fastening strain clamp drainage plate, replacing shock hammer, repairing wire, cleaning up and many other live working projects. The robot has advantages of overall flexibility, reasonable structural design, reliable shielding and protective performance, and convenient operation. Instead of manual work, it can be used to accomplish various live operation tasks for overhead transmission lines, which effectively avoiding potential safety hazards of high voltage, strong electric fields and high-altitude operations. The robot also greatly improves operating efficiency and reduces the labour intensity of humans. This paper describes a number of systems, such as the manipulator, the autonomous up and down system, the function control system, the wireless video transmission system, the remote control system and so on.

Study on Cracking of Aluminum Alloy Strain Clamps for 500kV Transmission Line

It was found that a large number of aluminum alloy strain clamps cracked. Cracking mainly occurred in the drainage plate of strain clamps. Nondestructive testing technologies and physicochemical analysis devices such as optical microscope, spectrograph, SEM and EDS were adopted to analyze the reasons of cracking. The results tell that there are numerous shrinkage cavities and cracks inside the drainage plate of strain clamps. The maximum area fraction of shrinkage cavities is 10.7%, and the maximum size is over 1mm2. A lot of shrinkage cavities and cracks gather together to form big flaws, which seriously reduce the mechanical properties of the drainage plates. After a long period of vibration, cracks gradually develop to the surrounding cavities and connect adjacent cavities. Eventually, cracks develop to the surface of drainage plates.

Development of Live-working Robot for Power Transmission Lines

Dream-I, the first reconfigurable live-working robot for power transmission lines successfully developed in China, has the functions of autonomous walking on lines and accurately positioning. This paper firstly described operation task and object of the robot; then designed a general platform, an insulator replacement end and a drainage plate bolt fastening end of the robot, presented a control system of the robot, and performed simulation analysis on operation plan of the robot; and finally completed electrical field withstand voltage tests in a high voltage hall as well as online test and trial on actual lines. Experimental results show that by replacing ends of manipulators, the robot can fulfill operation tasks of live replacement of suspension insulators and live drainage plate bolt fastening.

Performance assessment of tire chips–gravel mixes as leachate drainage layer material

Relative drainage performance of gravel and tire chips used alone and in different combinations were evaluated through the results of drainage plate settlement and leachate conductivity testing under incremental overburden pressure levels. Experiments were performed to assess the appropriate tire chips size (in particular aspect ratio) for their large-scale uses as leachate drainage layer material. Potential of clogging for the optimized size tire chips and their mixes with gravel of transmitting relatively “high-strength” leachate were also examined. Results showed that “small” size tire chips of aspect ratio 1 (average length 22–25 mm) are suitable for relatively lower drainage plate settlement and higher leachate conductivity values. Additionally, combinations with ds/dg = 0·25 and 0·50 (by thickness) when scrap tire chips and gravel were used as separate layers gave “lesser clogging and free drainage” up to higher vertical overburden pressure levels. Alternatively, 25% of tire chips (by weight) mixed randomly with gravel also gave lesser clogging and free drainage for relatively longer period. These findings are very useful for the proper design, performance and service life of tire chips–gravel made drainage layers.

Clinical Experience With a Novel Glaucoma Drainage Implant

To retrospectively evaluate the safety and efficacy of an Ahmed glaucoma valve (AGV) modified with a polyethylene shell (M4) to reduce the fibrotic reaction around the drainage plate compared with the S2 and FP7 models in patients with glaucoma. The medical records of patients who underwent implantation of the AGV FP7, S2, and M4 were reviewed. The primary outcome measure was cumulative probability of success, defined as an intraocular pressure (IOP) between 5 and 18 mm Hg and >20% reduction of IOP without loss of light perception, need for additional IOP-lowering surgical procedures, or removal of AGV. Seventy-six, 38, and 40 eyes received the FP7, S2, and M4 with a mean follow-up time of 578±157, 662±186, and 504±158 days, respectively. The mean IOP was reduced from 31.0±10.6 to 13.9±5.5 mm Hg in the FP7 group, 33.5±12.1 to 15.8±8.1 mm Hg in the S2 group, and 27.0±12.0 to 15.0±4.0 mm Hg in the M4 group at 1 year (P=0.31). At 1 year, the cumulative probability of success was 70%, 66%, and 80% and at 18 months, 61%, 53%, and 52% in the FP7, S2, and M4 groups, respectively (P=0.99). Complications were similar among groups. No significant difference was observed between the AGV M4, FP7, and S2 at 1 year. Additional follow-up is required to determine its long-term safety profile and efficacy.

Study on Construction Technology of Drain Board for Foundation Covered with Thicker Hardpan

In the paper, Construction technology and equipment improvement of plastic drainage boards driven in land area are studied. Because overlying hardpan is thick in some areas, drainage plate cant be driven by common vibratory board machine. In allusion to this instance, the machine was refitted to superficial drilling holes machine, a bore was drilled and then the drainage plate was driven to deal with the foundations covered with thick hardpan. Performance of this technology is researched and explored to deal with a complex foundation treatment by reclamation silt.

Analysis of the Treatment of Soft Soil Considering Rheological Property

viscoelasto-plastic; double yield surface; equivalent sand wall; finite element; Abstract. Based on double yield elastoplastic model, one viscoelasto-plastic model is dealt with in detail. The method of transferring to equivalent sand wall is introduced when soft soil is treated by plastic drainage plate. The viscoelasto-plastic model and modified Cam-Clay model are applied into the finite element calculation of soft foundation treatment of a tailing dam. By comparison, it can be got that the displacement calculated by the viscoelasto-plastic model is closer to monitoring data than that calculated by modified Cam-Clay model. It demonstrates the reasonableness and efficiency of the viscoelasto-plastic model．

A Study on Pore Diameter Distribution of Saliniferous Dredger Fill Consolidated by Vacuum Preloading

The pore structure of soil plays a decisive role in its engineering properties. In order to investigate the consolidation effect and pore distribution characteristic of saliniferous dredger fill after vacuum preloading, the indoor simulation experiments of vacuum preloading were carried out in two boxes, after vacuum preloading, the dredger fill was tested for its physicochemical and mechanical properties. Simultaneously, the mercury intrusion porosimetry was performed to obtain distribution of pore characteristic parameters, and analyzed its pore diameter distribution of dredger fill after vacuum preloading and the consolidation effect in the perspective of micro and macro. The research showed that the total pore volume and porosity of the No.1 box is lower than the No.2 box, and its bearing capacity and consolidation effect are much higher. When the dredger fill locates at the same distance from drainage plate, the deeper the dredger fill is buried, the smaller the porosity is, the better the bearing capacity and consolidation effect are. The pore of dredger fill in No.1 box is based mainly on meso pore, while the one in No.2 box is based mainly on meso pore and macro pore.

Experimental study on the dewatering behavior of the dredged mud with horizontal drainage by siphon method

The disposal of the dredged mud has become a worldwide problem recently. There are urgent demands for developing alternatives to dispose the dredged material in a more economical and environment-friendly manner. In this paper, siphon method is proposed to dewater the high-water-content dredged mud with horizontally installed plastic drainage plate. A series of parallel tests are conducted to preliminarily investigate the dewatering and strength behavior of the dredged mud with vacuum and siphon methods, respectively. On the basis of the test results, siphon method is proved to be an effective and energyfree approach to dewater the dredged slurry.

Biocompatibility response to modified Baerveldt glaucoma drains.

Glaucoma implants are designed to increase fluid outflow from the eye in order to decrease intraocular pressure and prevent damage to the optic nerve. The implant consists of a silicone tube that is inserted into the anterior chamber at one end and is attached at the other end to a silicone plate that is sutured to the outside of the globe beneath the conjunctiva. The glaucoma "implant" becomes a "drain" over the first 3 to 6 postoperative weeks as the silicone plate is enclosed by a fibrous capsule that allows a space to form into which fluid can drain and from which fluid can be absorbed by the surrounding tissues. Ideally, the size and thickness of the capsule (the filtering bleb) that surrounds the plate is such that the amount of fluid that passes through the capsule is identical to the amount of fluid produced by the eye at an intraocular pressure of 8 to 14 mmHg. The most common long-term complication of these implants is failure of the filtering bleb 2 to 4 years after surgery due to the formation of a thick fibrous capsule around the device. Micromovement of the smooth drainage plate against the scleral surface may be integral to the mechanism of glaucoma implant failure by stimulating low-level activation of the wound healing response, increased collagen scar formation, and increased fibrous capsule thickness. To test this hypothesis, we modified seven Baerveldt implants by adding porous cellular ingrowth material to the posterior surface of the drainage plate. Seven modified and five unmodified implants were placed in adult rabbit eyes. After 6 months, we found that the fibrous capsule around the modified implants was significantly thinner than the capsule surrounding the unmodified implants (p < 0.05), particularly on the surface between the porous ingrowth material and the sclera (p < 0.05). Although type I collagen predominated in the fibrous capsules around both types of implants, the amount of type III collagen in the capsules around the modified implants was significantly less than the amount around the unmodified implants (p < 0.05). We believe that these data suggest a reduction in the wound healing response to the modified implants, with greater stability of capsule thickness. Long-term studies are needed to verify that the stability of the capsules around the modified implants persists over a period of years, in which case this type of modification may prove useful in prolonging the functional life of these devices in the surgical treatment of glaucoma.