Can a building move more in one place while shaking less in another? That question opens this guide to 100 English seismic isolation vocabulary words. You will learn to describe structures, devices, motion, tests and performance claims, with definitions, natural collocations and original example sentences that turn technical language into understandable explanations.
Japan offers a concrete setting through the Japan Society of Seismic Isolation and research facilities such as NIED’s E-Defense. Their work makes the distinction between ground motion and building response especially useful. This article explores a particular field of Japanese engineering and research; it does not assume that every building uses the same system or that one technology represents every community’s experience.
Start with the motion diagnostic, then follow a route through ten-word groups. Use the fictional test comparison to practise “lower acceleration” and “larger displacement” without confusing them. “Top 100” is a curated learning list, not a frequency ranking. The diagrams described, figures and conversations here are classroom illustrations, not design specifications or results from a named Japanese building.
Choose the explanation you want to be able to give
A good route begins with the part you cannot yet explain. You may need a physical distinction, a measurement word or simply a clearer sentence.
A moving base is not automatically a failed building
Imagine a simplified model with a flexible isolation layer between its base and the structure above. A demonstration shows movement across that layer. Does the movement alone prove that the idea has failed? No. The next questions are what response was intended, what quantities were measured and how the observed motion compares with the system’s assessed limits.
Now consider two phrases: “the floor accelerated less” and “the isolation layer displaced more”. They refer to different quantities at different locations. Acceleration describes the rate of change of velocity; displacement describes a change in position relative to a reference. If the distinction is unclear, begin with group 4 before drawing conclusions from the worked example.
Finally, complete: “The result was lower than ___ under ___ conditions.” If you cannot fill both gaps, you do not yet have a useful comparison. Readers who know the physics but struggle to qualify a conclusion should begin with groups 8–10. Readers who can recite a definition but cannot point to its location in a diagram should start with groups 2–3.
Contents: choose a useful word group
Words 1–50
1–10: Earthquakes and the setting
11–20: The structure and its connections
Words 51–100
51–60: Testing and instruments
61–70: Looking after a functioning system
Worked example · Country context · Practice · Speaking and writing · Questions · Sources
These terms separate the earthquake source, local shaking and the conditions around a structure. A single adjective such as strong cannot perform all those jobs.
| No. | Word or term | Meaning and usage | Natural collocation | Original example |
|---|---|---|---|---|
| 1 | Seismic | Relating to earthquakes or earthquake-generated motion; an adjective. | seismic response | The report described seismic response rather than ordinary wind movement. |
| 2 | Earthquake | Sudden shaking associated with energy release within the Earth, commonly through fault slip. | earthquake motion | The model reproduced a selected earthquake motion for comparison. |
| 3 | Fault | A fracture or zone of fractures along which movement has occurred; not an equipment defect here. | active fault | The learner distinguished a geological fault from a faulty sensor. |
| 4 | Ground motion | Movement of the ground during an event; distinct from a building’s response. | recorded ground motion | The graph labelled the recorded ground motion separately from floor motion. |
| 5 | Magnitude | A measure describing an earthquake’s size at its source; not a local damage rating. | earthquake magnitude | The speaker did not use magnitude as a synonym for shaking in one room. |
| 6 | Intensity | A measure describing shaking effects or severity at a location, according to a stated scale. | local shaking intensity | The lesson distinguished local intensity from the earthquake’s magnitude. |
| 7 | Site | The location of a structure or investigation, including relevant ground conditions. | site conditions | The report stated that site conditions mattered to the assessment. |
| 8 | Soil | Unconsolidated ground material; its properties vary and require investigation. | soil properties | The student asked which soil properties the model represented. |
| 9 | Bedrock | Solid rock underlying soil or loose deposits; its depth and character vary. | depth to bedrock | The site sketch labelled depth to bedrock as a separate quantity. |
| 10 | Hazard | A potentially damaging event or physical condition; distinct from the resulting level of risk. | seismic hazard | The paragraph separated seismic hazard from the consequences for a particular building. |
Say what magnitude describes and what intensity describes. Neither word should be casually substituted for a measured floor acceleration.
Locate the parts before describing the mechanism. A building is a connected system, so the route through its components matters.
| No. | Word or term | Meaning and usage | Natural collocation | Original example |
|---|---|---|---|---|
| 11 | Structure | An arrangement of connected components that carries loads or serves a physical function. | building structure | The drawing showed the building structure without pretending to show every service. |
| 12 | Foundation | The part transferring a structure’s loads to the ground. | foundation system | The learner located the foundation system before describing the upper floors. |
| 13 | Superstructure | The main structure above the foundation or specified supporting level; define the boundary in context. | superstructure response | The chart identified which part of the superstructure was measured. |
| 14 | Column | A structural member commonly carrying loads mainly along its length, often vertical. | supporting column | The diagram labelled a supporting column beside the entrance. |
| 15 | Beam | A structural member commonly carrying transverse loads through bending. | floor beam | The student distinguished the floor beam from the vertical column. |
| 16 | Load | A force or other action imposed on a structure; specify its type. | vertical load | The explanation identified the vertical load supported by the bearings. |
| 17 | Load path | The connected route through which loads are transferred to supports. | continuous load path | The teacher asked the class to trace the load path on the drawing. |
| 18 | Connection | A joint or arrangement linking components; its behaviour matters to the system. | structural connection | The student marked the connection instead of assuming two touching lines were identical. |
| 19 | Isolation layer | The level containing components that allow the intended relative movement in an isolated structure. | seismic isolation layer | The animation highlighted movement across the isolation layer. |
| 20 | Clearance | Space provided between parts to permit movement or access; specify which purpose. | movement clearance | The model included clearance around the moving portion. |
Sketch a simple labelled arrangement. Mark the ground, isolation layer and structure above; do not let the word base refer to a different place in every sentence.
A device name is not a complete performance assessment. These words identify different components and physical functions.
| No. | Word or term | Meaning and usage | Natural collocation | Original example |
|---|---|---|---|---|
| 21 | Seismic isolation | A structural strategy using an isolation interface to alter transmitted motion and reduce selected responses. | seismic isolation system | The guide explained seismic isolation as a system rather than a magic material. |
| 22 | Isolator | A component allowing the intended relative movement while performing its supporting function. | seismic isolator | The diagram located the isolator between two labelled structural levels. |
| 23 | Bearing | A component supporting loads while permitting specified movement or rotation. | isolation bearing | The student asked what movements the isolation bearing was intended to permit. |
| 24 | Laminated rubber bearing | A bearing made with alternating bonded rubber and reinforcing layers, commonly steel. | laminated rubber bearing assembly | The cutaway illustration showed layers within the laminated rubber bearing. |
| 25 | Sliding bearing | A bearing that accommodates movement through sliding surfaces. | sliding bearing surface | The lesson distinguished a sliding bearing from the layered rubber example. |
| 26 | Damper | A device intended to dissipate mechanical energy and control motion. | energy-dissipating damper | The learner explained the damper’s function before naming its type. |
| 27 | Flexible joint | A connection designed to accommodate specified movement; not an accidentally loose connection. | flexible service joint | The drawing showed a flexible joint where a service crossed a moving interface. |
| 28 | Expansion joint | A joint or gap arrangement allowing relative movement between connected or adjacent parts. | building expansion joint | The caption identified the expansion joint as a movement detail. |
| 29 | Restoring force | A force tending to return a displaced system towards an equilibrium position. | provide restoring force | The simple model used a spring to illustrate restoring force. |
| 30 | Friction | Resistance associated with contacting surfaces and their relative motion or tendency to move. | sliding friction | The demonstration used sliding friction to discuss energy dissipation. |
Describe the intended function in plain English first. Then attach the technical term and check that you have not promised perfect behaviour.
Motion can be described in several ways. Location, direction, reference and unit belong beside each number.
| No. | Word or term | Meaning and usage | Natural collocation | Original example |
|---|---|---|---|---|
| 31 | Displacement | A change in position relative to a stated reference; it includes direction. | relative displacement | The graph showed displacement across the isolation layer. |
| 32 | Velocity | The rate of change of position, including direction; distinct from speed alone. | horizontal velocity | The learner labelled horizontal velocity with an appropriate unit. |
| 33 | Acceleration | The rate of change of velocity; it can occur when speed or direction changes. | floor acceleration | The sensor recorded floor acceleration during the test. |
| 34 | Amplitude | A measure of the size of an oscillation relative to its reference position. | oscillation amplitude | The diagram marked amplitude from the equilibrium position. |
| 35 | Peak | The greatest value or magnitude within a stated record; clarify the convention used. | peak acceleration | The report named the peak acceleration and the measurement location. |
| 36 | Residual displacement | Displacement remaining after the relevant motion or loading has ended. | measure residual displacement | The fictional test note recorded residual displacement after the run. |
| 37 | Drift | Relative lateral displacement between structural levels; state which levels are compared. | interstorey drift | The class distinguished interstorey drift from movement of the whole base. |
| 38 | Deformation | A change in shape or size under an action; not all deformation is permanent. | structural deformation | The drawing separated rigid-body movement from deformation. |
| 39 | Horizontal | Parallel to a level plane in the stated reference system; an adjective. | horizontal motion | The chart labelled horizontal motion separately from vertical motion. |
| 40 | Vertical | Aligned with the local up-and-down direction; an adjective. | vertical support | The explanation distinguished vertical support from horizontal flexibility. |
Practise “displacement relative to…” and “acceleration measured at…”. These short additions often repair an otherwise ambiguous explanation.
A simple oscillator offers vocabulary for discussing repeated movement. Real buildings are more complex, so keep the teaching model’s limits visible.
| No. | Word or term | Meaning and usage | Natural collocation | Original example |
|---|---|---|---|---|
| 41 | Oscillation | Repeated movement about a reference or equilibrium position. | free oscillation | The small teaching model continued its oscillation after release. |
| 42 | Cycle | One complete repetition of a recurring motion or process. | one motion cycle | The student marked one cycle on the simplified graph. |
| 43 | Period | The time taken for one complete cycle of repeated motion. | natural period | The learner expressed the period in seconds. |
| 44 | Frequency | The number of cycles per unit time; measured in hertz for cycles per second. | natural frequency | A longer period corresponded to a lower frequency in the example. |
| 45 | Resonance | A strong response when forcing interacts with a system near a natural frequency; damping affects it. | resonant response | The lesson discussed resonance using a simple oscillator. |
| 46 | Stiffness | Resistance to deformation under an applied force or action; not synonymous with strength. | lateral stiffness | The class compared lateral stiffness without claiming to compare failure strength. |
| 47 | Flexibility | The ability to deform or move under an action; the relevant direction matters. | horizontal flexibility | The explanation paired horizontal flexibility with vertical support. |
| 48 | Mass | A measure of inertia, commonly expressed in kilograms; distinct from weight as a force. | supported mass | The model description stated the supported mass. |
| 49 | Inertia | The tendency of an object to resist changes in its velocity. | inertial response | The student used inertia to explain why motion changes matter. |
| 50 | Damping | Processes that dissipate mechanical energy and reduce oscillatory response; not the same as making something wet. | damping effect | The comparison showed a damping effect in the teaching model. |
Contrast a longer period with a higher frequency. Then explain damping without suggesting that energy simply vanishes.
A test is an organised question put to a system. Instruments produce evidence that still requires context and interpretation.
| No. | Word or term | Meaning and usage | Natural collocation | Original example |
|---|---|---|---|---|
| 51 | Shake table | Equipment that imposes controlled motion on a test specimen. | shake-table test | The class watched a shake-table test and identified the input motion. |
| 52 | Specimen | The object or structure being tested; a technical experimental use. | full-scale specimen | The report described the specimen before presenting its response. |
| 53 | Full-scale | At the actual size relevant to the object represented; distinguish it from a reduced model. | full-scale testing | The explanation identified the purpose of full-scale testing. |
| 54 | Input | The motion, load or other quantity applied to a system in a test or analysis. | input motion | Both classroom models received the same specified input motion. |
| 55 | Response | How a system behaves under an input; name the measured quantity. | measured response | The measured response was reported at a particular floor. |
| 56 | Sensor | A device detecting a physical quantity and producing a signal. | acceleration sensor | The drawing showed the sensor location rather than only its name. |
| 57 | Accelerometer | An instrument that measures acceleration; it does not directly measure earthquake magnitude. | floor accelerometer | The floor accelerometer supplied the data for one graph. |
| 58 | Calibration | Establishing an instrument’s relationship to a reference; distinct from assuming it reads correctly. | instrument calibration | The laboratory note recorded calibration information. |
| 59 | Time history | A record of how a quantity varies with time; a technical data term. | acceleration time history | The time history showed more than the single peak value. |
| 60 | Repeatability | The closeness of results under repeated measurements with specified similar conditions. | test repeatability | The students asked how repeatability had been assessed. |
Read the setup description before the result. A striking graph without its input and sensor locations is an incomplete explanation.
The vocabulary extends beyond a demonstration. Components, records and connections have a continuing life after installation.
| No. | Word or term | Meaning and usage | Natural collocation | Original example |
|---|---|---|---|---|
| 61 | Inspection | A structured examination of condition or conformity; its scope should be stated. | scheduled inspection | The fictional record included a dated inspection entry. |
| 62 | Maintenance | Work intended to keep a system in suitable condition; generally uncountable. | planned maintenance | The discussion treated maintenance as continuing work. |
| 63 | Monitoring | Repeated or continuous observation of selected quantities or conditions. | structural monitoring | The report distinguished monitoring from a one-off photograph. |
| 64 | Accessibility | The ability to reach or use something; here it can refer to access for examination or work. | inspection accessibility | The drawing considered accessibility around the relevant component. |
| 65 | Replacement | Substitution of a component or material; requirements depend on the actual system. | component replacement | The learner asked what documentation accompanied the replacement. |
| 66 | Deterioration | A decline in condition over time; its cause and significance require assessment. | material deterioration | The report described deterioration without guessing its cause. |
| 67 | Documentation | Recorded information about design, work, condition or decisions. | maintenance documentation | The reader looked for documentation supporting the stated work. |
| 68 | Service life | The period during which something is expected or found to serve its intended function under stated conditions. | intended service life | The writer distinguished intended service life from a universal guarantee. |
| 69 | Retrofit | A modification to an existing structure or system to improve a specified function. | seismic retrofit | The article used retrofit for work on an existing building. |
| 70 | Continuity | The ability to maintain or resume an activity; specify the service and conditions. | operational continuity | The discussion separated structural performance from operational continuity. |
These entries teach how to read a description. They are not a checklist for inspecting or modifying a real building.
Performance is always performance at something. State the relevant objective and avoid turning one measured benefit into a universal guarantee.
| No. | Word or term | Meaning and usage | Natural collocation | Original example |
|---|---|---|---|---|
| 71 | Performance | How well a system meets stated objectives under specified conditions. | seismic performance | The student asked which measure defined performance in the report. |
| 72 | Criterion | A standard or condition used for judgement; plural criteria. | performance criterion | The report named the criterion before announcing success. |
| 73 | Limit | A stated boundary on a quantity, condition or claim. | movement limit | The learner asked which assessed limit applied to the comparison. |
| 74 | Capacity | The ability to withstand, carry or accommodate a specified demand. | displacement capacity | The chart did not confuse displacement capacity with observed displacement. |
| 75 | Demand | The action or response requirement imposed by a particular situation. | seismic demand | The discussion compared demand with the relevant capacity. |
| 76 | Risk | The possibility and consequences of adverse outcomes; depends on more than the hazard alone. | earthquake risk | The paragraph did not equate reduced response with zero risk. |
| 77 | Vulnerability | Susceptibility to damage or loss under a hazard; context and assets matter. | structural vulnerability | The learner distinguished vulnerability from the earthquake’s magnitude. |
| 78 | Damage | Physical harm or impairment; specify the component and severity. | nonstructural damage | The report discussed damage to contents separately from frame response. |
| 79 | Resilience | The capacity to withstand, adapt to and recover from disruption; specify the system considered. | community resilience | The discussion recognised that resilience extended beyond one device. |
| 80 | Limitation | A boundary on what a method, result or explanation establishes. | test limitation | The conclusion named a limitation of the single test. |
Complete the phrase “effective at reducing…”. If the object is missing, your reader cannot tell what the claim actually means.
A graph needs labels before it needs admiration. Comparisons become more useful when the measured quantity and conditions remain visible.
| No. | Word or term | Meaning and usage | Natural collocation | Original example |
|---|---|---|---|---|
| 81 | Baseline | A reference case or condition used for comparison. | baseline model | The isolated model was compared with a stated baseline. |
| 82 | Variable | A quantity or condition that can take different values. | controlled variable | The worksheet named the controlled variables in the comparison. |
| 83 | Unit | A defined standard for expressing a quantity, such as metres or seconds. | measurement unit | The learner checked the unit before comparing the numbers. |
| 84 | Axis | A reference line in a graph or coordinate system; plural axes. | vertical axis label | The axis label identified acceleration rather than displacement. |
| 85 | Trend | A pattern across a sequence of observations; not a synonym for one result. | response trend | The students needed several runs before discussing a trend. |
| 86 | Ratio | One quantity divided by another; comparable quantities and clear ordering matter. | response ratio | The report stated which value formed the numerator of the ratio. |
| 87 | Percentage reduction | A decrease relative to a stated baseline, expressed per hundred. | calculated percentage reduction | The learner named the baseline for the percentage reduction. |
| 88 | Uncertainty | A limit to knowledge or measurement precision; identify its source. | measurement uncertainty | The report described uncertainty rather than hiding it. |
| 89 | Assumption | A condition accepted for analysis that must be stated and examined. | modelling assumption | The simplified diagram made its assumption explicit. |
| 90 | Comparable | Sufficiently alike in relevant respects for a meaningful comparison. | comparable test conditions | The class checked comparable conditions before interpreting the results. |
Give the observation, identify the comparison and state one limit. Keep those three tasks in separate sentences at first.
These verbs help learners move from naming parts to explaining evidence. They are useful in science reports, interviews and everyday questions.
| No. | Word or term | Meaning and usage | Natural collocation | Original example |
|---|---|---|---|---|
| 91 | Transmit | Pass motion, force or energy through a connection or medium; specify what is transmitted. | transmit motion | The explanation traced how motion could be transmitted through the system. |
| 92 | Isolate | Reduce interaction or transmission through an appropriate interface; not necessarily eliminate it. | isolate the structure | The speaker explained the sense in which the system aimed to isolate the structure. |
| 93 | Dissipate | Convert organised mechanical energy into other forms, commonly heat in this context. | dissipate energy | The learner described how damping could dissipate energy. |
| 94 | Accommodate | Allow space or capacity for a required action or movement. | accommodate displacement | The joint was described as intended to accommodate displacement. |
| 95 | Measure | Determine a quantity using an instrument or method; state the location and unit. | measure acceleration | The test was designed to measure acceleration at a specified point. |
| 96 | Compare | Examine similarities and differences on a stated basis. | compare responses | The group compared responses under the same classroom input. |
| 97 | Evaluate | Assess evidence against a purpose or criterion; broader than noticing a number. | evaluate performance | The student asked which criteria were used to evaluate performance. |
| 98 | Reduce | Make a quantity smaller relative to a reference; it does not mean remove completely. | reduce floor acceleration | The conclusion said reduce floor acceleration rather than stop every motion. |
| 99 | Qualify | Limit or specify a statement so it matches the evidence; a communication verb here. | qualify a claim | The writer qualified the claim by naming the tested conditions. |
| 100 | Verify | Check a statement against appropriate evidence; distinct from repeating it confidently. | verify the comparison | The reader verified the comparison by checking the labels and setup. |
Choose verbs that match the evidence: suggests is not proves, and measures is not predicts. Precision can sound natural rather than timid.
Japan as a place to ask better engineering questions
The Japan Society of Seismic Isolation publishes explanations of isolation systems and their components. Its materials distinguish isolators and dampers and show details such as flexible joints. That is a useful starting point for vocabulary: a building’s response depends on an arrangement of parts, rather than one impressive object placed in a diagram.
NIED’s E-Defense facility description explains that full-size structures can be tested under complex three-dimensional motion. The educational point is the relationship between a controlled input and an observed response. A test facility provides a way to investigate behaviour; its existence does not prove that every building will perform identically.
This context supports several kinds of English use. A student may explain a graph. A museum visitor may ask what a demonstration represents. A future engineer may need to distinguish a component test from a whole-system claim. A resident reading a public explanation may want to know what “reduced shaking” actually measures. These are different audiences, but all benefit from precise nouns and properly limited comparisons.
Japan also contains varied regions, buildings, communities and experiences. Avoid sentences such as “Japanese buildings do not shake” or “everyone in Japan uses this technology”. They flatten both the engineering and the people. Describe the actual system or institution you have evidence for, and keep the country context proportionate to that evidence.
Three questions for reading an isolation diagram
First ask what supports the weight. In the simplified arrangement used here, components at an isolation interface support the structure above while allowing specified relative horizontal movement. Vertical support and horizontal flexibility describe different directions and functions. Saying that an interface is flexible does not mean it provides no support.
Second ask where movement is intended to occur. A drawing should identify the isolation layer and the structure above it. When you say “the building moved”, the reader may imagine several different things: motion of a floor, deformation between storeys or displacement across an isolation interface. Naming the location makes the sentence useful.
Third ask how the motion is being described. Displacement, velocity and acceleration are related but different quantities. You cannot decide which is larger by comparing an unlabelled number in millimetres with one in metres per second squared. Read the unit as part of the number, just as you read a surname as part of a person’s name.
A simple oscillator provides another contrast. A period of two seconds means one cycle takes two seconds; the frequency is half a cycle per second, or 0.5 hertz. A longer period corresponds to a lower frequency for that repeated motion. This calculation teaches the relationship between the words. It does not specify a suitable period for a real building.
Worked example: less acceleration, more relative movement
Consider an invented classroom comparison of two models under the same specified input. The baseline model has a peak floor acceleration of 4 metres per second squared. The model with an isolation interface has a peak floor acceleration of 2 metres per second squared at the corresponding location. Its interface also shows measurable relative displacement. These numbers are fictional and are not taken from a Japanese test.
What can we calculate? Relative to the baseline, the observed peak floor acceleration is lower by 2 metres per second squared. Dividing that reduction by the baseline value gives 2 ÷ 4 = 0.5, or 50%. A precise sentence is: “In this classroom comparison, the isolated model’s peak floor acceleration at the stated location was 50% lower than the baseline’s.”
What does the percentage not establish? It does not say that every response everywhere in the model fell by 50%. It does not measure damage, predict every future input or establish operational continuity. It certainly does not mean that the model did not move. The reported quantity is one peak acceleration at one location under one stated comparison.
Now add an invented observation: the isolation interface displaced more than the corresponding connection in the baseline arrangement. That does not contradict the lower floor acceleration. The statements concern different quantities and locations. The next useful question is whether the observed interface movement is consistent with the assessed behaviour and capacity of the system—not whether all movement has vanished.
Change one condition: suppose the two models received different input motions. The same arithmetic could still be performed on the two numbers, but attributing the difference to isolation alone would no longer be justified by that comparison. You would need to account for the changed input. This is the diagnostic breakpoint: can the learner preserve the calculation while withdrawing an unsupported causal claim?
For a short report, use four sentences: identify the comparison; state the measured result; calculate the reduction; name the limit. Read it aloud to a partner who has not seen the graph. If the partner cannot say what was measured and where, revise the sentence before adding any more engineering vocabulary.
A question that makes a demonstration more informative
This dialogue is invented. Visitor: “So the building becomes earthquake-proof?” Explainer: “The demonstration shows a lower measured response under this input. Which part would you like to compare?” Visitor: “The floor shaking.” Explainer: “Then let us look at the floor acceleration record and its sensor location.”
The explainer replaces a sweeping adjective with a measurable question. This is not a retreat from explaining the benefit. It is the step that makes the benefit intelligible. “Lower peak floor acceleration in this test” tells a reader something that can be checked. “Nothing can ever happen” does not.
Try a more conversational version: “It still moves, but we are looking at how it moves and where. This graph measures acceleration on the floor.” Then give the fuller technical version: “The comparison concerns peak acceleration at the specified floor location under the same input.” Moving between these registers is a useful English skill in its own right.
Do not turn the conversation into an inspection verdict about a real building. An actual assessment involves qualified professionals, relevant records and the particular structure. The learning task here is to understand a claim well enough to ask what evidence supports it.
Before describing the curve, read the frame around it
A graph title may say “response”, while the vertical axis says acceleration. The axis has supplied the missing specificity. Check the unit next, then the sensor location, then the input and time interval. Only after those checks should you describe a peak, ratio or trend.
A single peak compresses a whole record into one value. That can be useful, but it leaves out when the peak occurred and what happened during the rest of the motion. A time history preserves the sequence. Neither representation is automatically the correct choice for every question; state which question you are answering.
Compare this vague sentence: “The blue line is safer.” A stronger version is: “The blue record has a lower peak acceleration at the labelled location in this test.” If you wish to make a safety or performance judgement, identify the relevant criterion and supporting assessment. The graph alone may not contain them.
Finally, separate precision from confidence. A number written with many decimal places is not automatically accurate, and a clear label does not remove measurement uncertainty. The useful question is how the measurement was obtained and what precision is justified. English gives you enough room to be clear without pretending to know more than the evidence allows.
Practice: recall, explain and revise
1. Recall: which quantity describes the rate of change of velocity?
2. A simplified motion completes one cycle in four seconds. Find its frequency.
3. Repair: “A lower acceleration means no displacement.”
4. Calculate the reduction from a baseline value of 6 to a comparable value of 3.
5. Why should a report name the sensor location?
6. Distinguish stiffness from strength in ordinary language.
7. Qualify: “This test proves every building will be undamaged.”
8. Write a question about two tests with different input motions.
Answers and explanations
1. Acceleration. Displacement describes change in position; velocity describes its rate of change. Name the quantity and reference before comparing measurements.
2. The frequency is 1 ÷ 4 = 0.25 hertz. The period is four seconds. This is a vocabulary and arithmetic example, not a design recommendation.
3. “Acceleration and displacement are different quantities; lower acceleration does not establish zero displacement.” State the measurement locations if discussing a particular test.
4. The decrease is 3, and 3 ÷ 6 = 50%. Specify the quantity, baseline and comparable conditions; the percentage alone is not a complete engineering conclusion.
5. A measured response belongs to a location and direction. A floor record, ground record and interface measurement answer different questions even during the same event.
6. Stiffness concerns resistance to deformation under an action. Strength concerns resistance to failure or a specified limiting action. A stiffness comparison alone does not establish a strength comparison.
7. “This test provides evidence about the tested specimen under the specified input and conditions.” Wider claims need additional relevant evidence and assessment.
8. “How were the differences in input accounted for before attributing the response difference to the isolation system?” This asks for a fair comparison without rejecting the observations.
Use the words in a briefing someone can follow
For a student, prepare a sixty-second explanation of the fictional comparison. Use input, response, acceleration, displacement and baseline. Your listener should be able to tell which value was lower and why that does not mean zero motion. If the listener remembers only “it is safer”, make the measured quantity more explicit.
For a parent, ask the learner to draw three labelled locations before speaking: ground, isolation interface and measured floor. Point to one location and ask which quantity the sentence describes. This often reveals a misunderstanding more quickly than requesting a longer definition. Once the locations are stable, ask for one sentence without looking at the page.
For a teacher, separate three tasks: reading a unit, calculating a percentage and making a causal claim. A learner can calculate correctly while attributing a difference to the wrong cause. Change the input condition in the worked example and ask which sentence must be revised. This tests transfer rather than memorisation of the original answer.
For a learner interested in technical careers, practise two registers. Explain an isolation interface to a curious visitor in everyday language, then write a short technical caption with a location, quantity and limitation. Keep the conceptual content consistent across both versions. A more formal vocabulary should improve specificity rather than merely make the sentence longer.
The English Tuition | Japan guide discusses the gap between recognising English and using it independently. This article offers one concrete way to practise that transition. For a continuing sequence of meaning, context, recall and use, consult the eduKate Vocabulary Learning System. These learning links do not imply that eduKate operates a centre in Japan or that this list belongs to a particular Japanese examination.
Frequently asked questions
Is seismic isolation the same as making a building completely motionless?
No. Isolation systems allow intended relative movement and aim to reduce particular transmitted responses. Explain what is reduced, where it is measured and under which conditions. Avoid using motionless as a substitute for effective.
Does every building in Japan use seismic isolation?
No such claim is made here. Japan provides documented institutions and research examples, while buildings use varied structural approaches. A country label does not identify the system in a particular building.
Are magnitude and intensity interchangeable?
No. Magnitude describes earthquake size at its source, while intensity concerns shaking effects or severity at a location under a stated scale. A building’s measured response is another part of the account.
Why are there everyday words such as compare and qualify in a technical list?
Knowing component names is only part of communication. Those verbs help a learner connect evidence, identify a fair comparison and limit a conclusion. They are often the words that turn a technically decorated sentence into a useful explanation.
Can I use this article to assess a building?
It is an English-learning guide for reading and discussing technical descriptions. It does not provide design calculations, inspection criteria or a building-specific assessment. Use qualified professional assessment for decisions about an actual structure.
Which words should I learn first?
Start with ground motion, structure, isolation layer, input, response, displacement, acceleration, period, damping and comparison language. Explain one simple diagram with them, then expand into testing and performance vocabulary.
Is this an official examination vocabulary list?
No. It is an editorial selection designed for comprehension, discussion and writing. Match your practice to your actual course or communication task rather than treating the title as an examination requirement.
Sources and the scope of this guide
Sources were checked on 21 October 2026. Institutional publications support the setting and component descriptions; physics and earthquake references support the measurement distinctions. All numerical comparisons in this article are invented learning examples. No current building-count, cost, regulatory or guaranteed-performance claim is made.
Japan Society of Seismic Isolation: introductory booklet — Introductory explanation of isolation, supporting functions and motion.
Japan Society of Seismic Isolation: society pamphlet — Device categories and related connections; published October 2023.
NIED: E-Defense — The purpose of full-scale testing under three-dimensional motion.
USGS: earthquake magnitude, energy release and shaking intensity — The distinction between earthquake size and local shaking.
USGS: Earthquake Hazards Program glossary — Earthquake and motion terminology.
OpenStax: oscillations chapter summary — Period, frequency and simple oscillator relationships.
OpenStax: damped oscillations — Damping and the behaviour of a simplified oscillator.
Cambridge Dictionary: seismic — English meaning and use of seismic.
Your next route: explain one graph in four sentences
Use the fictional numbers above to write a four-sentence briefing. Name the models and input, identify the measured quantity and location, calculate the reduction, and state a limitation. Then replace the numbers and explain the comparison again without copying your first wording.
If the calculation is correct but the conclusion becomes a guarantee, return to group 8. If the conclusion is careful but the quantities are confused, return to group 4. When both are clear, explain the same result to a younger learner in ordinary language. That is a useful finish: accurate terminology that can travel into a real conversation.