Waterproof Design Research Articles

Analysis of Leakage Paths Induced by Longitudinal Differential Settlement of the Shield-driven Tunneling

It is a clear simplification to consider the tunnel lining as uniformly permeable. In reality, it is more likely that there are specific leaks, associated with segmental lining joints. In the case of the in situ concrete linings, construction joints can provide leakage paths, especially accounting for most of the water leakage. For transportation tunnels in saturated soils below water table, different settlements will lead to ring offsets and changes in joint opening near the edges where the gaskets are located and may significantly affect the sealant potential of the lining. In this paper, taking the metro line No.1 in Shanghai as an example, the development of joint opening and ring offset was set up based on the mechanical model of segment joint. Based on the magnitude of the joint opening or ring offset, the occurring of water leaking into the tunnel through the joint system can be judged. This analysis not only helps us realize the leakage paths of the segmental linings, but also provides the guidance for waterproof design and protection measures of the shield tunnel.

富水软弱地层地铁车站结构防水设计与渗漏水控制措施

富水软弱地层地下水渗流对在建地铁车站的施工安全与后期运营都存在重大危害。为此，依托深圳地铁7号线上沙车站结构防水工程，详细阐述了该车站结构防水设计原则与方法，揭示了结构缝隙渗漏水危害机理，提出了有效的控制措施，为富水软弱地层车站结构防水设计提供了重要参考。 The seepage of groundwater in the weak water-bearing strata has great harm to the construction safety and post-operation of the subway station. To this end, relying on the Shenzhen Metro Line 7 on the sand station structural waterproofing works, the principle and method of waterproof design of the station structure are expounded in detail to reveal the structural gap leakage water hazard mechanism. And put forward the effective control measures, which provides an important reference for the waterproof design of the water.

Modal and fatigue analysis of critical components of an amphibious spherical robot

With continuous improvements being made in science, technology, and production automation, robotics is becoming increasingly popular in the field of automation. Robotics has the potential to improve work efficiency, reduce production cost, protect humans from adverse conditions, and increase production scale. A three-dimensional (3D) printed amphibious spherical robot was designed to operate in various environments with a wide-range of complex conditions over a long period of time. The compact, fully waterproof design has the advantages of a reduced manufacturing time, high efficiency, good mobility, low noise, and reliable stability. This study considers how some of the more critical components of the robot, such as its leg brackets, circular middle plate, and spherical shell, respond to large dynamic stresses, shocks, and vibrations during operation; this can lead to reduced precision of the robot's locomotion and may cause critical components to become damaged or fail. To design the robot with a more rigid structure and improved dynamic characteristics, 3D models of the critical components were constructed with SolidWorks. Using ANSYS WORKBENCH software, these models were incorporated into the robot design to determine the natural frequencies and the associated mode shapes of the first six orders. The procedure and analysis results are described in this paper. The fatigue life of these critical components was examined using the cyclic load spectrum and cyclic stress as a function of number of cycles to failure (S---N curve) of acrylonitrile butadiene styrene plastic, the construction material for the robot. Finite element analysis was used for design optimization relevant to fatigue life, damage, safety, and fatigue sensitivity, and the weak areas in the components were identified. The approach described herein provides a theoretical basis for robotics design optimization.

Durability of Joint Components of Shield Tunnel under High Water Pressure in Erosion Environment

Based on the characteristics of the shield tunnel structure and marine environment, this paper discusses the durability factors affecting the joint components of shield tunnel. Based on engineering practices this study draws the conclusions as follows: the tidal water pressure causes the increase and decrease of the compression displacement of the rubber gasket, and reduces its fatigue lifetime; the impermeability of the rubber gasket is antagonistic to its lifetime in the condition of high water pressure, and its lifetime should coordinate with the service life of shield tunnel when the gasket meets the requirements of waterproof performance; the migration rate of chloride increases under high water pressure in erosion environment, which reduces chloride migration time to the surface of shield tunnel segment. Finally, the tree diagram of durability influencing factors of joint components under high water pressure in erosion environment is established, which will provide references for the waterproof design and the evaluation system of durability of joint components.

Flexible and waterproof micro-sensors to uncover zebrafish circadian rhythms: The next generation of cardiac monitoring for drug screening.

Flexible electronics are the next generation of sensors for mobile health and implantation. Zebrafish (Danio rerio) is an emergent strategy for pre-clinical drug development and toxicity testing. To address the confounding effects from sedation of fish and removal from the aquatic habitat for micro-electrocardiogram (µECG) measurements, we developed waterproof and wearable sensors to uncover the circadian variation in heart rate (HR) and heart rate variability (HRV) (Massin et al., 2000). The parylene-C based ECG sensor consisted of an ultra-soft silicone integrated jacket designed to wrap around the fish during swimming. The Young's modulus of this silicone jacket matched with the fish surface, and an extended parylene cable connected the underwater chest electrodes with the out-of water electronics. In addition, embedded micro-glass spheres in the silicone effectively reduced the effective density of the jacket to ~1 g cm(-3). These innovations enabled physiological ECG telemetry in the fish's natural habitat without the need for sedation. Furthermore, a set of non-linear signal processing techniques filtered out the breathing and electromagnetic artifacts from the recorded signals. We observed a reduction in mean HR and an increase in HRV over 24h at 10 dpa, accompanied by QT prolongation as well as diurnal variations, followed by normalization in mean HR and QT intervals at 26 days post ventricular amputation (dpa). We revealed Amiodarone-mediated QTc prolongation, HR reduction and HRV increase otherwise masked by sedation. The novel features of the flexible silicon jacket for µECG telemetry unraveled the biological clock and normalization of QT intervals at 26 dpa, providing the first evidence of new physiological phenomena during cardiac injury and repair as well as cardiac drug-mediated aberrant rhythms. Thus, the light weight and waterproof design holds promise to advance the next generation of mobile health and drug discovery.

Characteristic parameters’ optimization based on contact pressure of sealing gasket for segmental joints

The aim of this study is to optimize the characteristic parameters of the segmental joints based on the contact pressure of sealing gasket. The design status of shield tunnel segment joint sealing gasket material, cross-section type, and holes arrangement through statistical data are first analyzed using the numerical simulation method. The result of this study indicates that the linear regression analysis of the outer contour parameters of the gasket was carried out using the bottom edge length of the gasket as the control variable in accordance with the statistical samples, and the influence of geometric parameters on the waterproofing design of sealing gasket is analyzed by numerical simulation from the aspects of the number of closed holes, the shape of closed holes, and the change of the opening rate in different parts. Characteristic parameters optimization of rubber hardness parameters on waterproof design of sealing gaskets have been completed on the contact pressure of sealing gasket for segmental joints. It provided some references for the design, production, processing, and quality inspection of shield tunnel gasket in the future.

Research and Application of Coal Mine Rescue and Detecting Robots

Coal mine is a dangerous place in which many fatal factors menace miners' life. When some disasters occur, it may be very dangerous for rescuers to go into mine tunnels to search survivors. So developing the coal mine detecting and rescue robot for mine rescue has a very important meaning. In this paper, a system of explosion-proof detecting robot is presented. The structure design methods of robot have been discussed in detail, including robot body, computer control system, explosion-proof and waterproof design of systems, mobile mechanism design and software design. Finally the application results are given.

Seepage Filed Studies on the Effect of the Proposed Underground Garage

This paper intends to solve the leakage of the surface waters on the proposed underground garage impact from a practical engineering, so we carry on the detailed analysis about the surrounding hydro geological conditions to provide scientific basis for underground garage waterproof design. On that basis, we establish the hydro geological conceptual model, using Visual MODFLOW4.1 software to simulate the seepage field in two kinds of working conditions, and get the result of the surface waters on the proposed garage impact. Thus in the underground garage of the soleplate waterproof design we adopt different block waterproof practices which may save a lot of fund, and have the important theoretical and practical significance to us.

The Measurement of Water Bursting Volume of Jianfeng Mountain Tunnel and Treatment Techniques of Water Bursting

The measurement of tunnel water inflow is not only an important basis for engineering design changes, but also an effective verification of design. This paper combines with the analysis of the measured data of groundwater of large water inflow section, which appeared in the construction of high-speed Jianfeng mountain super long tunnel in Fuling Fengdu, Chongqing city, and detailed information of hydrological survey results. This paper has re-evaluated the engineering geology and hydro-geological of large gushing sections to clear the reason of water inflow, the development trend characteristics of groundwater and stability of surrounding rock. It is shown in this paper that the measures such as strengthening the support parameters, optimizing the waterproof and drainaging design schemes, and other measures can be adopted to ensure the safety of tunnel construction and effectively realize the concept of dynamic construction.

The Structure Design of Steel Structure Resident Building

With China's steel structure housing industry vigorously develop, the steel structure housing has been widely used in our country. In this paper, the steel structure housing structure and design essentials are introduced. Among design essentials, steel, the choice of connecting materials and wall materials, node design, the waterproof design of toilet and kitchen, floor systems design, the corrosion of steel structure, steel welding design and so on are mainly introduced.

Influence of Segment Design of Shield Tunnel on the Magnitude of Joint Opening

It is obviously a simplification to consider the tunnel lining as uniformly permeable.In reality it is more likely that there are specific leaks assocoated with segmental lining joints. In the case of in situ concrete linings, construction joints can provide leakage paths, accounting for most of the water leakage. In this paper, based on the mechanical model of segment joint, the analytical expression of magnitude of joint opening was developed, in light of which, the occurrence of water leakage through the joint system can be judged. Taking the metro line No.1 in Shanghai as an example, effects of such parameters as joint flexural stiffness, bolt location, bolt stiffness, bolt prestress, etc. on the magninitude of the joint opening were analyzed respectively through the analytical solution. The results not only help us realize the influence mechanism of segment design on the magnitude of joint opening of the segmental linings, but also provide the guidance for waterproof design of the shield tunnel.

Polymer mems-based fabry-perot shear stress sensor

This paper reports a novel optical fiber-based micro-shear stress sensor utilizing a flexible membrane and double SU-8 resist structures as a moving micro-mirror, together with an optical fiber as a micro-Fabry-Perot interferometer. This sensor can be employed in air or liquid environments with high sensitivity because of its waterproof design. Through UV lithography processes on thick SU-8 resist, the roughness of the reflection surface has approached 7 nm (Ra value), suitable for optical applications. A single-mode optical fiber is employed for detecting the displacement of the floating element induced by shear stress. Tests have been carried out successfully and a detection possibility of 10 nm-displacement of the floating element and a displacement sensitivity of 0.128 nm/nm (spectrum shift/floating element displacement) has been demonstrated. The temperature coefficient of this fiber-optic sensor has been characterized to be 3.4 nm/K linearly from 25 to 48/spl deg/C. Fluid tests have also been performed by placing the sensor inside the inner wall of a precisely machined rectangular channel and the result shows a sensitivity of 0.4 nm/ml/min (spectrum shift/flow rate), corresponding to a shear stress resolution of 0.65 Pa/nm (shear stress/spectrum shift). The minimum detectable shear stress is thereby estimated as 0.065 Pa from the reading resolution of the spectrometer of 0.1 nm, comparable to its counterparts with resolutions from 0.1-1 Pa.

THE WATERPROOFNESS OF STRUCTURAL DIAPHRAGM WALLS.

Keywords BUTLER PULLER WALLS, STRUCTURAL, DIAPHRAGM, WATERPROOFNESS, WATERTIGHT, LEAKAGE, WATER, WATERPROOF, DESIGN, STANDARDS, BASEMENTS, CONSTRUCTION, PREVENTION, LININGS, PANELS, JOINTS, SLABS, SPECIFICATIONS, GROUND, GROUNDWATER... Show All