Bridge Support Research Articles

The Financial Obligations of the Shareholder

The vast theme “Financial obligations of the shareholder” requires some restrictions. This means that a comparative overview and comparison with other legislatures will not be presented in the following; my remarks are based on and confined to German corporate law. While it is true that basic traits of our European company law systems are commonly shared (as regards financial obligations of the shareholders, in particular due to the 2nd Company Law Directive of the EU), many differences remain. Hence it is left to the foreign reader to find similarities or differences in her or his own system with what follows here. A second restriction has to be made and mentioned. The chapter does not deal with the well-known debate about the usefulness of the traditional European system of a nominal capital which of course has implications for the financial duties of shareholders as regards the formation of a company; the raising of fresh capital; and for distribution of profits and assets to the shareholders (“capital maintenance”). The general debate about this has stalled meanwhile as the results of the various studies on the pros and cons of the different systems were inconclusive. An interesting side issue in this debate is the usefulness of a minimum capital requirement for smaller corporations which do not fall under the provisions of the 2nd Company Law Directive. Like other European legislations Germany has reacted to the regulatory competition triggered by the rulings of the EU Court of Justice in the well-known cases on the “immigration” of foreign companies by the introduction of the “One Euro-Company” (“haftungsbeschrankte Unternehmergesellschaft”; UG). The UG is a limited liability company (GmbH) with a stated capital below EUR 25,000 and not less than EUR 1. Hence the financial obligations of the founding shareholders are reduced accordingly. As the UG makes profits, however, it has to set aside one-quarter of the annual distributable profits into a special reserve until the amount of EUR 25,000 has been reached. I will get back to that in more detail below. After the introduction of this form of company the “invasion” of foreign companies (mostly British Ltds.) has come to a halt, due perhaps both to the attractiveness of this new form and because the market found out that the foreign company forms are not all that attractive (foreign company law is applicable; difficult and unsettled conflicts of laws arise; there is a costly duty to file annual accounts drawn up in English and reviewed by foreign accountants with a foreign commercial register). Another issue relating to financial obligations of the shareholder concerns open or hidden disbursements of company assets outside regular distribution of profits, the sanctions for such disbursements as well as other actions which lead or may lead to damages for creditors of the company. Apart from the sanctions provided for explicitly in our company and civil law the German Federal Supreme Court (Civil Matters) has developed recently a claim based on the reproach of an intervention of shareholders which destroyed the very existence of the company (“existenzvernichtender Eingriff”). This fits into the general discussion about in which cases German company law acknowledges a direct liability of the shareholder, a discussion which cannot be taken up here. The chapter refers to the legal framework in Germany; an English version of the laws mentioned in the following can be accessed on the homepage of the EMCA group. The chapter will first deal with the financial duties of shareholders when forming a company (see §13.02). In a further section, the duties when new shares are issued will be discussed (see §13.03). Of particular interest for the foreign reader may prove the new regulation of shareholder loans as a financing tool (see §13.04). If the company is in financial distress, the shareholders may provide voluntary bridge support and waive certain rights (see §13.05). The question of whether there is an obligation of the shareholder to finance a company in financial distress will then be dealt with (see §13.06). The chapter will end with a summary and conclusion (see §13.07).

Studying the effect of partial blockage on multi-vents bridge pier scour experimentally and numerically

Abstract The local scour depth at bridge supports due to partial blockage on front of multi-vents bridge pier is studied experimentally and numerically. The existence of blockage such as debris and industrial wastes, leads to increase the local scour depth around bridge foundation and even bridge failure. The computational fluid dynamic program (SSIIM), is applied to simulate the scour around bridge supports. The numerical model used the finite-volume method to solve the Navier-Stokes equations. The k – e turbulence model is applied to solve the Reynolds-stress term. The 3-D flow model has been verified by comparing the numerical simulation with experimental data. It was found that, the local scour depth by impermeable obstruction on front of one bridge pier depends on Froude number, and dimensions of obstacle. In addition, multiple linear repressions are used to propose empirical equations for estimating local scour depth at bridge supports. The results show good agreement between both of numerical and statistical simulations with experimental results.

Baseline MELD-XI score and outcome from veno-arterial extracorporeal membrane oxygenation support for acute decompensated heart failure.

Acute decompensated heart failure is the most common acute heart failure phenotype. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) can provide bridging support for patients with acute decompensated heart failure to transplantation. We studied the association between baseline (<6 months), pre-ECMO (<24 h) parameters and outcome of VA-ECMO support in patients with severe acute decompensated heart failure. We included 26 consecutive patients with acute decompensated heart failure (acute myocarditis, myocardial infarction or post-cardiotomy shock were excluded) who were bridged with peripheral VA-ECMO to transplantation. Data within six months (baseline) and immediately pre-ECMO were collected. Model for end-stage liver disease (MELD) with sodium (MELD-Na) and without international normalized ratio (MELD-XI) scores were calculated. Outcome was defined as death at 30 days following VA-ECMO support. Thirteen of the 26 patients died within 30 days of VA-ECMO support. Univariate associations with 30-day mortality were baseline MELD-XI, baseline sodium, creatinine, bilirubin, pre-ECMO alanine aminotransferase and lactate. However, only baseline MELD-XI score (hazard ratio 2.678 (95% CI 1.085-6.607), p=0.033) was associated 30-day survival on logistic regression analysis. Survivors demonstrated greater reduction in inotropic and vasoactive drug support and improvement in alanine aminotransferase and lactate levels. Using a threshold based on the median MELD-XI of 14.1, 30-day survival in patients with a baseline MELD-XI ⩽ 14.1 was 69% compared with 31% in patients with baseline MELD-XI > 14.1 ( p=0.046). Baseline MELD-XI score, but not pre-ECMO parameters, is independently associated with outcomes from VA-ECMO support in patients with acute decompensated heart failure.

“Technique to Improve Retention &amp; Support for Natural Tooth Pontic Resin Bonded Bridge.”

Use of natural tooth (autologous or homologous) as pontic for resin bonded bridges in anterior region of jaws, present many advantages in cases where other treatment options are precluded due to poor economic condition of the patient. Two methods are used to connect the natural tooth pontic to abutments i.e. either by directly bonding the pontic to abutment teeth using composite resin, or by use of bonded metal framework to attach pontic to abutment teeth. In either case high long term failure rates are reported to be due to inadequate retention & support to the pontic. A technique is illustrated to improve retention & support of natural tooth pontic in the following clinical report.

Seismic Fragility Analysis of Reinforced Concrete Bridges with Chloride Induced Corrosion Subjected to Spatially Varying Ground Motions

This paper studies the time-dependent seismic fragility of reinforced concrete bridges with chloride induced corrosion under spatially varying ground motions. The time-varying characteristic of the chloride corrosion current density and the uncertainties related to the structural, material and corrosion parameters are both considered in the probabilistic finite element modeling of the example RC bridge at different time steps during its life-cycle. Spatially varying ground motions at different bridge supports are stochastically simulated and used as inputs in the fragility analysis. Seismic fragility curves of the corroded RC bridge at different time steps are generated using the probabilistic seismic demand analysis (PSDA) method. Numerical results indicate that both chloride induced corrosion and ground motion spatial variations have a significant effect on the bridge structural seismic fragility. As compared to the intact bridge, the mean peak ground accelerations (PGAs) of the fragility curves of the RC bridge decrease by approximately 40% after 90 years since the initiation of corrosion. Moreover, the effect of ground motion spatial variations changes along with the process of chloride induced corrosion owing to the structural stiffness degradation. Neglecting seismic ground motion spatial variations may not lead to an accurate estimation of the lifetime seismic fragility of RC bridges with chloride induced corrosion.

Stability and Marginal Bone Level Changes of SLActive Titanium-Zirconium Implants Placed with Flapless Surgery: A Prospective Pilot Study.

Immediately-loaded, narrow-diameter implants can be a less invasive alternative for the implant-supported fixed rehabilitation of narrow, posterior crests. To determine the stability and marginal bone level (MBL) changes of narrow-diameter, titanium-zirconium (TiZr) implants placed with flapless surgery and loaded immediately in the posterior region. Thirty-eight TiZr implants (3.3 mm diameter, 10 mm length, Roxolid, Straumann AG) were placed in the posterior crests of 14 patients with computer-guided flapless surgery as a support of 3-unit posterior bridges. Eighteen implants were loaded immediately, and 20 implants were loaded conventionally. The implant stability quotients were determined at the 1, 2, 4, and 8. weeks of healing before conventional loading, and at the 3, 6, and 12. months after loading by resonance frequency analysis. The MBL changes were measured by digital radiography. The surgical protocols were accomplished without any biological complications. There was no significant difference in the stability changes of TiZr implants between the loading groups (p > .05). The MBL changes were -0.18 ± 0.27 mm and -0.24 ± 0.27 mm at the 12. month of immediate and conventional loading, respectively, which was not statistically significant (p > .05). The stability and MBL changes of TiZr implants supporting posterior 3-unit bridges were clinically acceptable at the first year of loading.

Monitoring of Scour Around Bridge Piers and Abutments

Scour of the riverbeds around bridge supports is the most frequent cause of their failures. Maintenance and repair costs of the bridges damaged by scour effects are significant, but it is estimated that the social costs are five times higher than the direct repair and replacement costs.The bridge supports are subjected to the scour effects due to the erosive action of the flowing water, involving soil loosening from the bottom and the banks of the watercourse. The condition for the proper monitoring of scour is to understand its nature. The knowledge of the phenomena occurring during the high water flow in the area of the bridge supports is crucial to properly assess the current condition and to develop proper maintenance actions.Scour may be the consequence of:•narrowing the watercourse – a natural or man-made, including construction of a bridge,•lateral movement or lowering of the stream bed,•hydraulic works shortening the length of the meandering section of the watercourse,•changes occurring in the catchment area of the watercourse,•other changes in watercourse hydrology.Construction of a bridge in the certain area disturbs natural stream flow conditions, especially the flood water and may change the terms of the normal water flow. The presence of a bridge causes the stream flow cross-section reduction, which increases the speed and intensity of erosion of the streambed. River tends to stabilize its bed in order to restore the natural flow section. Bridge supports also change the laminar water flow and turbulent flow.Scour present around a bridge supports can be monitored by the mobile and fixed devices.Portable scour monitoring devices are mainly: different types of probes such as: sticks, tape or rope with weights and bars used by divers and sonar acoustic measuring devices.Stationary equipment is used for continuous or regular scour monitoring of the bridge supports of the bridge, for example once a day, once a week. They are stationary devices including various types of robotic probes and stationary hydroacoustic measurement systems. Stationary device can be installed on a support or near the bridge, usually at the head of the pillar, or in the ground near the bottom of the watercourse. It should be installed near the site of the anticipated greatest scour. The device interacts with the data logger, which can be read on the site or transmitted to a remote control unit.The article presents the principles of scour monitoring near the bridge supports, developed during the project “Monitoring system for bridge supports and their surrounding areas” co-founded by the Polish National Centre for Research and Development under the program Innotech. During the project monitoring system for bridge supports was developed with specialized software for online data visualization. The article presents selected measurement results from the sonar measurements.

EXPERIMENTAL STUDY ON THE EFFECT OF PERMEABLE BLOCKAGE AT FRONT OF ONE PIER ON SCOUR DEPTH AT MULT-VENTS BRIDGE SUPPORTS

Debris accumulation around bridge supports can constrict and redirect flow through the muti-vents bridges resulting in significant bridge foundation scour. The experimental study of this paper, aims to investigate the effect of different porosities of partial blockage at front of bridge pier on local scour depth formed around bridge supports. The permeable blockage with different relative heights (H/Bp= 0.4, 0.8 and 1.2) was fixed on and above the mobile bed. It was found that, for 15% porosity ratio of permeable blockage, the local scour depth at the left pier and right abutment was increased by 11.3% and 20% respectively compared to the no-blockage case. In addition the permeable blockage that placed at the water surface produces more local scour depth at multi-vents bridge supports compared to its location on the mobile bed.

Обзор упрочняюще-пассивирующих методов ударного поверхностного пластического деформирования

In article is made the scientific substantiation and the practical confirmation of possibility, expediency and high efficiency of application of technology of impact superficial plastic deformation in zones of welded connections after performance of welding works is given. Is described the mathematical model of process of the superficial plastic deformation, describing this process, as the hypercycle of loading consisting of elementary cycles - blows and a method of operative control of process with use of the standard portable devices included in the state register of measuring instruments. The technology is recommended to use during the manufacturing and repair of any metal mantles in places of dimensional and structural nonuniformity such as mechanical defects and the microcracks, damages of a surface owing to corrosion, constructive elements which are sharply changing a relief of a surface and under the influence of the enclosed external forces become zones of concentration of mechanical tension and cause the tensely-deforming conditions. Advisably hardening in such places of walls of the vessels working under pressure and having operational loadings in the form of the tangential stretching mechanical tensions generalized equivalent characteristics for which is described by a known formula of boiler or its special cases: pipes of gaz-, oil, vapor- and water supply systems, steam and water coppers, caissons and vessels of other appointment. The scope of applications of described technology can include installation and repair the sea and river ships or of floating objects of oil production. The technology can be applied to improvement of operational characteristics of details of mechanical engineering and transport, objects of energetic and construction: surfaces of a rolling and sliding of machines, cars and devices, wheels of a rolling stock of railway transport, a metalwork of support of power lines, platforms and bridges for the purpose of counteraction a fatigue at cyclic loadings and corrosion, increase of wear resistance.

The 2016 International Society for Heart Lung Transplantation listing criteria for heart transplantation: A 10-year update

Mandeep R. Mehra, MD (Chair), Charles E. Canter, MD, Margaret M. Hannan, MD, Marc J. Semigran, MD, Patricia A. Uber, PharmD, David A. Baran, MD, Lara Danziger-Isakov, MD, MPH, James K. Kirklin, MD, Richard Kirk, MD, Sudhir S. Kushwaha, MD, Lars H. Lund, MD, PhD, Luciano Potena, MD, PhD, Heather J. Ross, MD, David O. Taylor, MD, Erik A.M. Verschuuren, MD, PhD, Andreas Zuckermann, MD and on behalf of the International Society for Heart Lung Transplantation (ISHLT) Infectious Diseases, Pediatric and Heart Failure and Transplantation Councils

Rotational Angle Measurement of Bridge Support Using Image Processing Techniques

Measuring a very small rotational angle accurately and dynamically is indeed a challenging issue, especially in the case of bridge support. Also, existing inclinometers do not have sufficient resolution and accuracy to measure a bridge’s rotational angle. In this study, a new measurement system was developed to provide a practical means for measuring dynamic rotational angle of a bridge support. It features high resolution and accuracy compared with the available systems on the market. By the combinational use of a laser pointer and a vision-based displacement measurement system, the measurement accuracy was significantly increased. The accuracy and applicability were investigated through laboratory tests. From the laboratory tests, it has been found that the developed system can be applicable to bridge support with very small rotational angle. The effectiveness of the developed system was verified through field tests on real bridges. From the full-scale implementation on two PSC girder bridges, it is observed that the proposed system can measure the rotational angle with a high accuracy and reliability.

Computer-Aided Rehabilitation of Maxillary Oncological Defects Using Zygomatic Implants: A Defect-Based Classification

A complete maxillectomy for neoplastic lesions leads to serious oral dysfunction. Zygomatic implants for fixed bridge support are considered beneficial for maxillary defects after tumor resection. This clinical study examined the management of patients with different maxillary defect types who underwent delayed rehabilitation using zygomatic implants and immediate prosthetic loading. Virtual preoperative planning and intraoperative navigation were performed in all cases. Five patients were treated with this new method. The total number of zygomatic implants positioned was 17. Four patients had immediate loading of a fixed prosthesis and 1 had delayed loading. One patient had 1 failed implant. The use of preoperative virtual surgical planning and an intraoperative navigation system allows the surgeon to achieve safer implant positioning in a complex anatomic site. A systematic bone defect classification was created and a specific treatment protocol is proposed for each type of defect.

The Influence of Distance Variation between Rings with Sloping Position on the Cylinder Surface to Drag Coefficient

There are so many equipment using cylinder in its application, such as bridge support column, smoke chimney, pole pillar of offshore oil drilling etc. When those kind of equipment is affected by air flow continuously, it would reducing the strength of those equipment construction. This strength reduction is caused by the drag force that is emerged due to the air flow and its direction are having the same direction with flow direction. So that it is necessary to do something to reduce the drag, one of it is by adding the rectangular ring at the cylinder surface. The rings is placed at the cylinder surface in 100sloping position and then its ring distance would be varied. The aim of this research is to discover the influences of distance variation between the ring with sloping position on the cylinder surface to the drag coefficient. This research is conducted in the wind tunnel that consist of blower, pitot pipe, U manometer, inclined manometer, digital weight, cylinder, quadrangular rings (attached on the cylinder). The cylinder is placed in vertical position within the distance between the rings is varied as L/D = 0.5, 0.67, 0.83, 1.00, and 1.17. The Reynold number based on silinder diameter D = 60 mm is Re = 3.64 X 104. Pressure distribution is determined by measuring cylinder surface pressure at 36 points with 100interval. The result of this research showed that the lowest drag coefficient value occurs at the distance between the ring of L/D = 0.5 is 0.485. The large decreasing of the drag coefficient compare to without rings is 43.5%.

Diagnostics of an Existing Cable-Stayed Bridge by Means of the Dynamic Load Test

The cable-stayed bridge at the inner ring road in Prague in the Czech Republic was put into operation in 1997. In 2008 a crack was found in the bridge structure area where the end beam was connected with the upper deck of the box section and where the bridge expansion joint system was anchored. The basic objective of diagnostic works, which were started immediately after the finding of the crack, was obtaining the basis for bridge structure modifications, among other things, to prevent formation of similar damages in the future. A series of diagnostic methods was used for determination of the bridge actual state and the real static and dynamic bridge behavior. One of these methods was the dynamic load test. It was focused on an examination of the bridge forced vibration which was caused by dynamic effects of a usual traffic flow. An arrangement of the test was not quite usual because the experiment was concentrated on dynamic behaviour of bridge support areas especially. The abutment area, the pylon area and the area of a pillar with the bearing with a tensile structural element were observed on the investigated bridge. The dynamic load test was performed in two stages. The first stage was focused on investigation of bridge dynamic behaviour in original structural conditions and on obtaining the basis for design of bridge adjustments. The second stage was realized after bridge reconstruction in December 2012 and verified the effectiveness of bridge modifications.

Diagnostics of a Historical Bridge Using Measuring Methods and Inverse Analysis

The article deals with diagnostics of a historical bridge using measuring methods and inverse analysis and presents selected results of the pilot project implemented for the Railway Infrastructure Administration, state organization. The main task is to fulfill the function of an owner/operator of the national and regional railway owned by the state in Czech Republic. Main results of the project will be used for the reconstruction of the similar historical bridges on railway lines in the Czech Republic. Non-geodetic measurements include the determination of actual module of elasticity of the masonry, which was determined by direct measurement of the selected bridge support. Geodetic measuremets include long-term (seasonal epochs) and short-term (continuous during the load test) monitoring of geometrical deformations of the “Křenová” historical railway bridge construction in Brno.

Experimental investigation of local scour around multi-vents bridge piers

The harmful effect of local scour around bridge piers and abutments can induce high maintenance costs or even bridge collapse resulting in the disturbance of traffic and possibly human losses. In the present research, an experimental study was carried out to investigate local scour around multi-vents bridge supports. Different methods of scour-countermeasures were applied to minimize and control the formed scour around bridge supports. It was found that, using collar around piers, current deflectors and sacrificial pile upstream piers reduced local scour depth by more 90%.

Students as Producers: The Postgraduate Teaching Assistant Pilot Project

This paper reports on a pilot project in which two postgraduate students were supported to function in the role of teaching assistants (TAs) as part of their learning experience. The project embraced the notion of students as producers rather than consumers. Using a reflective approach, this case study was jointly written by TAs and their teaching staff. It incorporates feedback from other students collected through an anonymous module feedback survey, which was analysed by attribution to themes. The role of TAs benefitted others students, staff, and the TAs; the project is a strong affirmation of the principle of treating students as producers. The impact of the role on both the students undertaking the TA role and the tutors was profound, and student experience was enhanced as a result. TAs can assist in bridging student-teacher communication gaps and support students’ learning through sharing their knowledge by creating resources. This article is written from the perspectives of both the TAs and the tutors.

Dynamic interaction between vehicle and bridge deck subjected to support settlement

Many bridges inevitably experience foundation settlement during their lifetime. Structural engineers need to limit the foundation settlement so that the bridge structure does not develop intolerable stresses. One factor in the effect of foundation settlement on bridge structures that has not been considered so far is the dynamic interaction between bridge and moving vehicle. In this study, Hamilton principle is adopted to derive the governing equations for the vibration of line supported orthotropic thin plates due to moving vehicles. The effect of foundation settlement on the bridge–vehicle interaction (BVI) is investigated by modifying the interaction forces due to the deformed shape of deck. The effect of fully or partially developed membrane stresses on the BVI will be also discussed. The results show that dynamic load allowance (IM) increases depending on the support location where settlement occurs, mode of settlement, span length, and magnitude of the foundation settlement. However the effect of membrane stresses on IM is insignificant. The analysis results indicate importance of considering the effect of bridge support settlement on the dynamic BVI.

3D numerical simulation of turbulence and sediment transport within a tidal inlet

Turbulence and sediment transport models are incorporated into a three-dimensional hydrodynamics model to investigate the mechanisms of morphologic evolution of scour holes within the Indian River Inlet, Delaware, USA. The inlet bed had eroded slightly since stabilizing the channel walls in late 1930s through 1976. The mean rate of bed erosion roughly doubled as a response to anthropogenic activities within the inlet such as the removal of ~80 piles remaining from an old bridge. Severe erosion near the in-water bridge supports and cofferdams for the replacement bridge necessitated channel bed stabilization that along with the remained debris from the removal of old bridge piles enhanced the growth of two deep scour holes on the bayside and oceanside of the bridge cofferdams. Scour hole and channel bed evolution has decreased drastically since 1994. The present investigation suggests that, initially, flow concentration through the cofferdams of the replacement bridge was the main reason for scour hole development. Bed shear stress over the forward-facing slope of the scour hole entrains sediment from the bed and extends the scour hole along the inlet and in the vertical direction. Flow separation within the developed scour holes after channel bed stabilization enhances turbulence and appears to be the dominant mechanism for further scour hole development.

Seismic vulnerability of box girder continuous bridges under spatially variable ground motions

In seismic design of extended multi-span bridges the question always arises whether using either natural or artificially generated earthquake records that are identical at all bridge supports is valid or not. It is likely that earthquake ground motion remarkably differs at the various support/pier locations in terms of amplitude, frequency content and arrival time, inducing under certain circumstances significant forces and deformations that would not develop if the assumption of synchronous excitation was adopted. This paper hence illustrates the impact of ground motion spatial variability on the seismic performance and vulnerability of extended continuous box girder bridges in both bridge orthogonal directions (longitudinal and transverse). For illustration purposes, a nine-span bridge with a total length of 430 m is adopted. Non-linear time history analyses are carried out using opensees software. The effects of the spatial variability in the ground motions at the different bridge supports are investigated using a set of 20 artificially simulated seismic ground motions generated using sim software developed in the mid-nineties, considering different degrees of loss in coherency and various soil types (i.e., frequency contents). Results of the non-linear time history analyses performed in an incremental dynamic analysis context are hence manipulated through a probabilistic analysis framework to generate fragility curves associated with various performance levels for the case study bridge. Fragility curves giving the conditional probability of exceeding various performance levels are then integrated with generated hazard curves defining the expected seismic hazard in Egypt. The outcome of this integration process results in values of mean annual frequency of exceeding pre-defined performance levels.