What is “preset” during installation of bridge bearings?

What is “preset” during installation of bridge bearings?
by

1 Answer

Answer :

“Preset” is a method to reduce the size of upper plates of sliding bearings in order to save the material cost. The normal length of a upper bearing plate should be composed of the following components: length of bearing + 2 x irreversible movement + 2 x reversible movement.  Initially  the bearing is  placed at the mid­point of the upper bearing plate without   considering   the   directional   effect   of   irreversible   movement.   However,   as irreversible   movement   normally   takes   place   at   one   direction   only,   the   bearing   is displaced/presetted a distance of (irreversible movement/2) from the mid­point of bearing in which the length of upper plate length is equal to the length of bearing + irreversible movement + 2 x reversible movement. In this arrangement, the size of upper plate is minimized in which irreversible movement takes place in one direction only and there is no need to include the component of two irreversible movements in the upper plate.
Note: “Preset” refers to the displacement of a certain distance of sliding bearings with respect to upper bearing plates during installation of bearings.
by

Related questions

In a curved prestressed bridge, how should the guided bearings in piers of the curved region be oriented with respect to the fixed bearing in abutment?

Description : In a curved prestressed bridge, how should the guided bearings in piers of the curved region be oriented with respect to the fixed bearing in abutment?

Last Answer : To determine the orientation of guided bearings, one should understand the movement of curved region of a prestressed bridge. Movement of prestress and creep are tangential to the curvature of the ... large, temporary freedom of movement at the guided bearings has to be provided during construction.

What Do You Understand By “preset” During The Installation Process Of Bridge Bearings?

Description : What Do You Understand By “preset” During The Installation Process Of Bridge Bearings?

Last Answer : Answer : During the installation of bridge bearings the size of the upper plates is reduced to save the material costs. This process is known as preset. Generally the upper bearing plate comprises of ... to the length of the length of the bearing + irreversible movement + 2 x reversible movement

Polytetrafluoroethylene (PTFE) is commonly used in sliding bearings. Why?

Description : Polytetrafluoroethylene (PTFE) is commonly used in sliding bearings. Why?

Last Answer : The choice of sliding surface of bearings is of vital importance because the sliding surfaces generate frictional forces which are exerted on the bearings and substructure of the bridge. For ... be designed with dimples to avoid the lubricant from squeezing out under repeated translation movements.

Under what situation should engineers use pot bearings instead of elastomeric bearings?

Description : Under what situation should engineers use pot bearings instead of elastomeric bearings?

Last Answer : In the event of high vertical loads combined with large angle of rotations, rubber bearings are undesirable when compared with pot bearings. For instance, elastomeric ... bearings are better alternatives than elastomeric bearings in such an scenario as suggested by David J. Lee.

What is the advantage of sliding bearings over roller bearings?

Description : What is the advantage of sliding bearings over roller bearings?

Last Answer : In roller bearing for a given movement the roller bearing exhibit a change in pressure centre from its original position by one­half of its movement based on David J. Lee. However, with sliding ... built in the substructure. It follows that there is no change in pressure center after the movement.

How to determine the size of elastomeric bearings?

Description : How to determine the size of elastomeric bearings?

Last Answer : For elastomeric bearing, the vertical load is resisted by its compression while shear resistance of the bearing controls the horizontal movements. The design ... and fatigue damage. The vertical stiffness of bearings is obtained by inserting sufficient number of steel plates.

In the design of elastomeric bearings, why are steel plates inserted inside the bearings?

Description : In the design of elastomeric bearings, why are steel plates inserted inside the bearings?

Last Answer : For elastomeric bearing to function as a soft spring, the bearing should be allowed for bulging laterally and the compression stiffness can be increased by limiting the amount of lateral bulging. To ... , the presence of metal plates does not affect the shear stiffness of the elastomeric bearings.

In incremental launching method of bridge construction, what are the measures adopted to enhance sufficient resistance of the superstructure during the launching process?

Description : In incremental launching method of bridge construction, what are the measures adopted to enhance sufficient resistance of the superstructure during the launching process?

Last Answer : i) During the launching process the leading edge of the superstructure is subject to a large hogging moment. In this connection, steel launching nose typically about 0.6­0.65 times span length is ... . iii)For very long span bridge, temporary piers are provided to limit the cantilever moment.

What is sucker deck principle for variable depth bridge decks?

Description : What is sucker deck principle for variable depth bridge decks?

Last Answer : For a variable depth bridge deck, the depth of continuous multi­span bridge deck is increased in pier supports and this absorbs sagging moments in the ... of arches and curved soffit rather than boring uniform deck alignment. Reference is made to Brian Pritchard (1992).

Should raking piles of a bridge abutment be placed under an embankment?

Description : Should raking piles of a bridge abutment be placed under an embankment?

Last Answer : For a bridge abutment to be supported on raking piles with different orientations, the movement between the ground and the pile group is difficult to predict. For instance, if some of the raking ... experience severe bending moment and damage the piles as recommended by Dr. Edmund C Hambly (1979).

In joints of precast concrete bridge segments, what are the functions of applying epoxy adhesive?

Description : In joints of precast concrete bridge segments, what are the functions of applying epoxy adhesive?

Last Answer : Epoxy adhesive is applied in these joints for the following purposes according to International Road Federation (1977): (i) It seals up the joints completely between precast concrete segments to protect the ... in transferring of shear between the joints in case a large single shear key is used.

In the design of a simply supported skew bridge, which direction of reinforcement should be provided?

Description : In the design of a simply supported skew bridge, which direction of reinforcement should be provided?

Last Answer : In the conventional design of steel reinforcement for a simply supported skew bridge, a set of reinforcement is usually placed parallel to free edge while the other set is designed parallel ... ). In this way, considerable savings would be obtained from the orthogonal arrangement of reinforcement.

In the construction of a two­span bridge (span length = L) by using span­by­span construction, why is a length of about 1.25L bridge segment is constructed in the first phase of construction?

Description : In the construction of a two­span bridge (span length = L) by using span­by­span construction, why is a length of about 1.25L bridge segment is constructed in the first phase of construction?

Last Answer : Basically, there are mainly three reasons for this arrangement: (i) The permanent structure is a statically indeterminate structure. During construction by using span­by­span construction, if the ... 25L from the first pier where there is relatively more space to accommodate prestressing works.

In bridge widening projects, the method of stitching is normally employed for connecting existing deck to the new deck. What are the problems associated with this method in terms of shrinkage of concrete?

Description : In bridge widening projects, the method of stitching is normally employed for connecting existing deck to the new deck. What are the problems associated with this method in terms of shrinkage of concrete?

Last Answer : In the method of stitching, it is a normal practice to construct the widening part of the bridge at first and let it stay undisturbed for several months. After that, concreting will then be ... Stitching refers to formation of a segment of bridge deck between an existing bridge and a new bridge.

How do engineer determine the number of cells for concrete box girder bridges?

Description : How do engineer determine the number of cells for concrete box girder bridges?

Last Answer : If the depth of a box girder bridge exceeds 1/6 or 1/5 of the bridge width, then it is recommended to be designed as a single cell box girder bridge. However, if the bridge depth is ... improvement in transverse load distribution when the number of cells of box girder is increased to three or more.

What are the shortcomings of grillage analysis which is commonly used in structural analysis of bridges?

Description : What are the shortcomings of grillage analysis which is commonly used in structural analysis of bridges?

Last Answer : Grillage analysis suffers from the following shortcomings based on E. C. Hambly: (i) For coarse mesh, torques may not be identical in orthogonal directions. Similarly, twists may differ in ... moment in an element depends on the curvatures in the beam's direction and its orthogonal direction.

What are the functions of grout inside tendon ducts?

Description : What are the functions of grout inside tendon ducts?

Last Answer : Grout in prestressing works serves the following purposes: (i) Protect the tendon against corrosion. (ii) Improve the ultimate capacity of tendon. (iii) Provide a bond between the structural member and the tendon. (iv) In case of failure, the anchorage is not subject to all strain energy.

Why is the span length ratio of end span/approach span to its neighboring inner spans usually about 0.75?

Description : Why is the span length ratio of end span/approach span to its neighboring inner spans usually about 0.75?

Last Answer : From aesthetic point of view, an odd number of spans with a decrease in length in the direction of abutment is desirable. Moreover, spans of equal length are found to be boring. However, the ... the last span in a continuous bridge while approach span refers top the first span of a bridge.

What are the three major types of reinforcement used in prestressing?

Description : What are the three major types of reinforcement used in prestressing?

Last Answer : i) Spalling reinforcement Spalling stresses are established behind the loaded area of anchor blocks and this causes breaking away of surface concrete. These stresses are induced by strain incompatibility with ... of action of the load. Reinforcement is needed to resist these lateral tensile forces.

Are diaphragms necessary in the design of concrete box girder bridges?

Description : Are diaphragms necessary in the design of concrete box girder bridges?

Last Answer : Diaphragms are adopted in concrete box girder bridges to transfer loads from bridge decks to bearings. Since the depth of diaphragms normally exceeds the width by two times, they are usually designed ... In fact, diaphragms also contribute to the provision of torsional restraint to the bridge deck.

In prestressing work, if more than one wire or strand is included in the same duct, why should all wires/strands be stressed at the same time?

Description : In prestressing work, if more than one wire or strand is included in the same duct, why should all wires/strands be stressed at the same time?

Last Answer : If wires/strands are stressed individually inside the same duct, then those stressed strand/wires will bear against those unstressed ones and trap them. Therefore, the friction of the trapped wires is high and is undesirable.

Sometimes the side of concrete bridges is observed to turn black in colour. What is the reason for this phenomenon?

Description : Sometimes the side of concrete bridges is observed to turn black in colour. What is the reason for this phenomenon?

Last Answer : In some cases, it may be due to the accumulation of dust and dirt. However, for the majority of such phenomenon, it is due to fungus or algae growth on concrete bridges. After rainfall, the ... help to solve this problem. Reference is made to Sandberg Consulting Engineers Report 18380/X/01.

What are the advantages of assigning the central pier and the abutment as fixed piers?

Description : What are the advantages of assigning the central pier and the abutment as fixed piers?

Last Answer : (i) For abutment pier to be assigned as fixed pier while the bridge is quite long, the longitudinal loads due to earthquake are quite large. As the earthquake loads are resisted by fixed piers, the size of ... Therefore, the size of movement joints can be reduced significantly.

Under what situation shall engineers use jacking at one end only and from both ends in prestressing work?

Description : Under what situation shall engineers use jacking at one end only and from both ends in prestressing work?

Last Answer : During prestressing operation at one end, frictional losses will occur and the prestressing force decreases along the length of tendon until reaching the other end. These frictional losses include the ... if the total span length is sufficiently long, jacking from both ends should be considered.

What Kind Of Preset Should I Use On Handbrake?

Description : What Kind Of Preset Should I Use On Handbrake?

Last Answer : Honestly, just give it a shot and use whatever preset produces the results you like. You won't ruin your movie or delete your computer or anything. So try all of the ones you have access to ... , and compare the final results, then continue to use the preset that produces the results you like best.

$ In Basidiomycetes, there are preset dikaryotic cells called Synkaryons. ! Four exogenous spored are produced in Ascomycetes.

Description : $ In Basidiomycetes, there are preset dikaryotic cells called Synkaryons. ! Four exogenous spored are produced in Ascomycetes.

Last Answer : $ In Basidiomycetes, there are preset dikaryotic cells called Synkaryons. ! Four exogenous spored are produced in ... D. If both As and R are wrong.

A radioactive element is preset in VIII group of the periodic table. If it emits one `alpha`particle, the new position of the nuclide will be

Description : A radioactive element is preset in VIII group of the periodic table. If it emits one `alpha`particle, the new position of the nuclide will be

Last Answer : A radioactive element is preset in VIII group of the periodic table. If it emits one `alpha`particle, the new ... . VI B B. VIII C. VIIB D. I B

Does this microwave have special preset functions, such as sensor cooking or preset time buttons?

Description : Does this microwave have special preset functions, such as sensor cooking or preset time buttons?

Last Answer : Yes, the Hotpoint 15 CuFt Over The Range Microwave oven does have special preset functions, such as sensor cooking and preset time buttons.

Which of the following is a special type of credit card with stored money value? A. Preset Value Card B. Stored Value Card C. Both(A) & (B) D. None of the Above

Description : Which of the following is a special type of credit card with stored money value? A. Preset Value Card B. Stored Value Card C. Both(A) & (B) D. None of the Above

Last Answer : B. Stored Value Card Explanation: A stored-value card is a payments card with a monetary value stored on the card itself, not in an external account maintained by a financial institution. Stored- ... deposit with the issuer, and credit cards which are subject to credit limits set by the issuer.

Which is an interest-free period that is to be given by a creditor to debtor? A. Fixed Period B. Preset Period C. Grace Period D. None of the Above

Description : Which is an interest-free period that is to be given by a creditor to debtor? A. Fixed Period B. Preset Period C. Grace Period D. None of the Above

Last Answer : C. Grace Period Explanation: The grace period is the provision in most loan and insurance contracts which allows payment to be received for a certain period of time after the actual due date. During ... will be charged, and the late payment will not result in default or cancellation of the loan.

Which plant parameters shown in the illustration would produce an alarm if they exceeded preset values? EL-0094 A. SME #7 CYL. EXH. and L.O. TO RDCN. GR. B. L.O. PRESS. TO MN. ENG. and PME #3 MN. BRG. C. L.O. PRESS. TO MN. ENG. and L.O. TO RDCN. GR. D. PME #3 MN. BRG. and SME #7 CYL. EXH.

Description : Which plant parameters shown in the illustration would produce an alarm if they exceeded preset values? EL-0094 A. SME #7 CYL. EXH. and L.O. TO RDCN. GR. B. L.O. PRESS. TO MN. ENG. and PME #3 MN. BRG. C. L.O. PRESS. TO MN. ENG. and L.O. TO RDCN. GR. D. PME #3 MN. BRG. and SME #7 CYL. EXH.

Last Answer : Answer: D

Which plant parameters shown in the illustration would produce an alarm if they fell below preset values? EL-0094 A. SME #7 CYL. EXH. and L.O. PRESS. TO RDCN. GR. B. L.O. PRESS TO MN. ENG. and PME #3 MN. BRG. C. L.O. PRESS. TO MN. ENG and L.O. PRESS. TO RDCN. GR. D. PME #3 MN. BRG. and SME #7 CYL. EXH.

Description : Which plant parameters shown in the illustration would produce an alarm if they fell below preset values? EL-0094 A. SME #7 CYL. EXH. and L.O. PRESS. TO RDCN. GR. B. L.O. PRESS TO MN. ENG. and PME #3 MN. BRG. C. ... . TO MN. ENG and L.O. PRESS. TO RDCN. GR. D. PME #3 MN. BRG. and SME #7 CYL. EXH.

Last Answer : Answer: C

An instantaneous-trip-type fuse will _____________. A. open as soon as the load current exceeds its set point B. allow a preset delay between overcurrent and melting C. open a circuit by using a time delay element with a magnetic trip D. reset itself when the overcurrent is corrected

Description : An instantaneous-trip-type fuse will _____________. A. open as soon as the load current exceeds its set point B. allow a preset delay between overcurrent and melting C. open a circuit by using a time delay element with a magnetic trip D. reset itself when the overcurrent is corrected

Last Answer : Answer: A

In_ instructions are followed one after the other in the preset order in which they appear within program: a. Sequence b Selection c. Break d. Iteration

Description : In_ instructions are followed one after the other in the preset order in which they appear within program: a. Sequence b Selection c. Break d. Iteration

Last Answer : a. Sequence

The background of any Word document - 1) is always white colour 2) is the colour you preset under the Options menu 3) is always the same for the entire document 4) can have any colour you choose Ans: 2) ✐ The blinking symbol on the c

Description : The background of any Word document - 1) is always white colour 2) is the colour you preset under the Options menu 3) is always the same for the entire document 4) can have any colour you choose

Last Answer : 2) is the colour you preset under the Options menu

A nose wheel control system a. Prevents the nosewheel from castering at all times b. Allows the nosewheel to caster within preset limits about the neutral position c. Allows the nosewheel to caster freely at all times d. Prevents the nose gear from lowering if the nosewheels are not centralised

Description : A nose wheel control system a. Prevents the nosewheel from castering at all times b. Allows the nosewheel to caster within preset limits about the neutral position c. Allows the nosewheel to caster freely at all times d. Prevents the nose gear from lowering if the nosewheels are not centralised

Last Answer : b. Allows the nosewheel to caster within preset limits about the neutral position

A nose wheel control system a. Prevents the nosewheel from castering at all times b. Allows the nosewheel to caster within preset limits about the neutral position c. Allows the nosewheel to caster freely at all times d. Prevents the nose gear from lowering if the nosewheels are not centralised

Description : A nose wheel control system a. Prevents the nosewheel from castering at all times b. Allows the nosewheel to caster within preset limits about the neutral position c. Allows the nosewheel to ... freely at all times d. Prevents the nose gear from lowering if the nosewheels are not centralised

Last Answer : b. Allows the nosewheel to caster within preset limits about the neutral position

The output of a JK flipflop with asynchronous preset and clear inputs is ‘1’. The output can be changed to ‘0’ with one of the following conditions. (A) By applying J = 0, K = 0 and using a clock. (B) By applying J = 1, K = 0 and using the clock. (C) By applying J = 1, K = 1 and using the clock. (D) By applying a synchronous preset input.

Description : The output of a JK flipflop with asynchronous preset and clear inputs is 1'. The output can be changed to 0' with one of the following conditions. (A) By applying J = 0, K = 0 and using a clock. (B) ... (C) By applying J = 1, K = 1 and using the clock. (D) By applying a synchronous preset input.

Last Answer : Ans: C Preset state of JK Flip-Flop =1 With J=1 K=1 and the clock next state will be complement of the present state.

State functions of preset, clear, clock and SR inputs related to SR flip flop.

Description : State functions of preset, clear, clock and SR inputs related to SR flip flop.

Last Answer : Preset Input: is an asynchronous input to set the Q output to 1 Clear Input: is also asynchronous input to reset the Q output to 0 Clock Input: is used to input external logic clock pulse (HIGH-LO) to ... set the Q output. And R is the reset input which is used to reset Q output of the flipflop.

State function of preset and clear in flip flop.

Description : State function of preset and clear in flip flop.

Last Answer : In the flip flop , when the power is switched on, the state of the circuit is uncertain i.e. may be Q = 1 or Q = 0.  Hence, the function of preset is to set a flip flop i.e. Q = 1 and the function of clear is to clear a flip flop i.e. Q = 0.

The output of a JK flip-flop with asynchronous preset and clear inputs is ‘1’. The output can be changed to ‘0’

Description : The output of a JK flip-flop with asynchronous preset and clear inputs is ‘1’. The output can be changed to ‘0’ with one of the following conditions by applying A) J = 0, K = 0 and using a clock B) J = 1, K = 0 and using the clock C) Asynchronous preset input D) J = 1, K = 1 and using the clock 

Last Answer : The output of a JK flip-flop with asynchronous preset and clear inputs is ‘1’. The output can be changed to ‘0’ with one of the following conditions by applying J = 1, K = 1 and using the clock 

Prismatic compass is considered more accurate than a surveyor's compass, because (A) It is provided with a better magnetic needle (B) It is provided with a sliding glass in the object vane (C) Its graduations are in whole circle bearings (D) It is provided with a prism to facilitate reading of its graduated circle

Description : Prismatic compass is considered more accurate than a surveyor's compass, because (A) It is provided with a better magnetic needle (B) It is provided with a sliding glass in the object vane ( ... whole circle bearings (D) It is provided with a prism to facilitate reading of its graduated circle

Last Answer : (D) It is provided with a prism to facilitate reading of its graduated circle

The bearings of two traverse legs AB and BC are N52° 45' E and N34° 30' E respectively. The deflection angle is (A) 18° 15' E (B) 18° 15' N (C) 18° 15' W (D) 18° 15' L

Description : The bearings of two traverse legs AB and BC are N52° 45' E and N34° 30' E respectively. The deflection angle is (A) 18° 15' E (B) 18° 15' N (C) 18° 15' W (D) 18° 15' L

Last Answer : (D) 18° 15' L

The bearings of the lines AB and BC are 146° 30' and 68° 30'. The included angle ABC is (A) 102° (B) 78° (C) 45° (D) None of these

Description : The bearings of the lines AB and BC are 146° 30' and 68° 30'. The included angle ABC is (A) 102° (B) 78° (C) 45° (D) None of these

Last Answer : (A) 102

There are two stations A and B. Which of the following statements is correct? (A) The fore bearing of AB is AB (B) The back bearing of AB is BA (C) The fore and back bearings of AB differ by 180° (D) All the above

Description : There are two stations A and B. Which of the following statements is correct? (A) The fore bearing of AB is AB (B) The back bearing of AB is BA (C) The fore and back bearings of AB differ by 180° (D) All the above

Last Answer : (D) All the above

The effective span of a simply supported slab, is (A) Distance between the centres of the bearings (B) Clear distance between the inner faces of the walls plus twice the thickness of the wall (C) Clear span plus effective depth of the slab (D) None of these

Description : The effective span of a simply supported slab, is (A) Distance between the centres of the bearings (B) Clear distance between the inner faces of the walls plus twice the thickness of the wall (C) Clear span plus effective depth of the slab (D) None of these

Last Answer : Answer: Option B

The effective span of a simply supported slab is (a) Distance between the centers of the bearings (b) Clear distance between the inner faces of the walls plus twice he thickness of the slab. (c) Cleat spa plus effective depth of the slab. (d) All the above

Description : The effective span of a simply supported slab is (a) Distance between the centers of the bearings (b) Clear distance between the inner faces of the walls plus twice he thickness of the slab. (c) Cleat spa plus effective depth of the slab. (d) All the above

Last Answer : (c) Cleat spa plus effective depth of the slab.

In centrifugal pump installation, (A) Pump is properly primed before starting (B) The diameter of the pipe at inlet as well as at outlet, is kept smaller than the delivery pipe (C) The motor may burn out if it is started with empty delivery pipe and with open gate valve (D) All the above

Description : In centrifugal pump installation,  (A) Pump is properly primed before starting  (B) The diameter of the pipe at inlet as well as at outlet, is kept smaller than the delivery pipe  (C) The ... out if it is started with empty delivery pipe and with open gate valve  (D) All the above 

Last Answer : (D) All the above 

When upgrading or installing an operating system why is it important to document any problems during the installation and the settings chosen?

Description : When upgrading or installing an operating system why is it important to document any problems during the installation and the settings chosen?

Last Answer : What is the answer ?