Sand cone check gear offers a exact and sensible technique for figuring out the quantity of soil. Understanding its basic ideas, parts, and working procedures is essential for correct geotechnical evaluation. This information gives a complete overview, from the essential principle to superior purposes and security concerns.
This gear performs an important position in numerous engineering tasks, providing a dependable strategy to measure soil properties. Various kinds of sand cone check gear cater to numerous wants, providing various capacities and ranges of precision. The detailed process ensures correct knowledge assortment, whereas a comparative evaluation of the gear’s options, together with capability and accuracy, assists in knowledgeable choice.
Introduction to Sand Cone Take a look at Tools
The sand cone technique is an important method for precisely figuring out the quantity of soil samples, a basic step in geotechnical engineering. This technique, recognized for its simplicity and relative ease of use, depends on a fastidiously managed course of to measure the exact quantity displacement of a selected soil mass. It is an indispensable device for understanding soil properties and enabling knowledgeable selections in development tasks.The basic precept behind the sand cone technique lies within the exact measurement of the quantity of a recognized mass of sand.
The recognized quantity of sand is poured right into a cone-shaped system. Then, the soil pattern is positioned contained in the cone, and the quantity of sand wanted to fill the area beforehand occupied by the soil is exactly measured. This displacement of sand straight correlates to the quantity of the soil pattern. The accuracy of the sand cone technique relies upon closely on the constant management of the sand pouring course of and the cautious dealing with of the soil pattern.
Sand Cone Take a look at Tools Sorts
Numerous varieties of sand cone check gear can be found, every designed for particular purposes and soil sorts. These variations stem from elements like the specified capability, the extent of precision required, and the vary of soil volumes to be measured.
Comparability of Sand Cone Take a look at Tools Fashions
| Mannequin | Options | Capability (cm3) | Accuracy (cm3) | Typical Purposes |
|---|---|---|---|---|
| Mannequin SC-100 | Light-weight, moveable design, appropriate for area testing; fundamental options | 100-200 cm3 | ± 0.5 cm3 | Discipline investigations, preliminary assessments, small-scale tasks |
| Mannequin SC-500 | Sturdy development, excessive precision scale, a number of calibration choices; supreme for detailed testing | 500 cm3 | ± 0.2 cm3 | Detailed laboratory evaluation, high quality management, development tasks requiring excessive accuracy |
| Mannequin SC-PRO | Excessive-capacity design, automated sand meting out, superior digital show for exact measurements | 1000-2000 cm3 | ± 0.1 cm3 | Massive-scale tasks, analysis research, in depth soil testing applications |
The desk above highlights the important thing variations between numerous sand cone check gear fashions. Completely different fashions cater to various wants, with completely different capacities and ranges of precision to accommodate a variety of tasks. The selection of apparatus must be guided by the precise mission necessities. As an illustration, a small-scale website investigation would possibly solely require a fundamental mannequin, whereas a large-scale civil engineering mission would seemingly profit from a extra superior and complicated mannequin.
Elements of Sand Cone Take a look at Tools
Unveiling the secrets and techniques of soil mechanics, the sand cone check offers invaluable insights into the quantity of voids inside a pattern. Understanding the intricate elements of this equipment is vital to correct and dependable outcomes. This exploration delves into the crucial parts and their features throughout the sand cone testing process.The sand cone check, a basic technique in geotechnical engineering, permits for the willpower of the quantity of voids in soil samples.
This information is essential for understanding the soil’s properties, that are crucial in numerous engineering purposes, together with basis design and highway development. By meticulously analyzing the parts and their roles, we achieve a deeper understanding of this highly effective device.
Key Elements and Their Capabilities
The sand cone equipment is a meticulously designed meeting of interconnected elements, every enjoying a selected position within the testing course of. Correct measurements depend on the exact functioning of those parts.
- The Cone: An important element, the cone is fastidiously designed for exact quantity measurements. It sometimes encompasses a slim opening to manage the move of sand. The cone’s exact form is important for managed and constant sand discharge, guaranteeing correct quantity calculations. This precision in design straight impacts the reliability of the check outcomes. Variations in cone design can result in important inaccuracies.
- The Funnel: Positioned above the cone, the funnel directs the sand move, stopping spillage and guaranteeing that sand is deposited uniformly into the cone. Its design influences the uniformity of sand discharge, impacting the accuracy of the measurement. A funnel with a easy, well-defined opening is important for environment friendly and dependable sand move.
- The Container: This holds the soil pattern and facilitates the position of the sand cone equipment. The container’s measurement and form are chosen based mostly on the soil pattern’s quantity. Correct choice of the container is essential for accommodating the pattern with out inflicting any disturbance or leakage. A container that is too small or too massive can skew the outcomes of the check.
- The Sand: The sand used within the cone check is particularly chosen for its uniformity and dry traits. Its particle measurement distribution, dry density, and moisture content material are very important elements that have an effect on the accuracy of the check. A standardized kind of sand is important for constant outcomes. Completely different sand sorts will result in inconsistent outcomes.
Diagram of Sand Cone Take a look at Tools
Think about a fastidiously crafted funnel, funneling sand right into a exactly formed cone, with a container under, holding the soil pattern. This setup permits for the exact measurement of the soil pattern’s quantity. The picture under depicts the association of the important thing parts.
A diagram would present a funnel positioned above a cone, the cone positioned above a container. The container would maintain the soil pattern. The association clearly demonstrates the sequential technique of filling the cone with sand.
Specs of Important Elements
The desk under summarizes the specs for the crucial parts, providing an in depth understanding of the bodily attributes.
| Part | Description | Typical Specs |
|---|---|---|
| Cone | Cone form for sand filling | Particular quantity, dimensions for correct quantity measurement. |
| Funnel | Directs sand move into cone | Dimension and form for managed move. |
| Container | Holds soil pattern and sand cone equipment | Dimensions appropriate for the soil pattern quantity. |
| Sand | Specified sand kind | Uniform particle measurement, dry traits. |
Process for Performing the Sand Cone Take a look at: Sand Cone Take a look at Tools
Unveiling the secrets and techniques of soil quantity willpower, the sand cone check emerges as a vital technique in geotechnical engineering. This exact method permits engineers to quantify the quantity of soil samples, a basic step in understanding soil properties and traits. From laboratory settings to area purposes, the sand cone check stands as a cornerstone in soil evaluation.Precisely figuring out the quantity of soil is important in quite a few geotechnical investigations.
This understanding types the idea for numerous calculations, together with void ratios, densities, and moisture contents. The sand cone check, a time-tested technique, ensures dependable and constant outcomes, underpinning essential selections in engineering tasks. The check’s precision lies within the meticulous management over the sand’s move and the meticulous measurement of its displaced quantity.
Normal Process for the Sand Cone Take a look at
The sand cone check includes fastidiously managed steps, guaranteeing constant and correct outcomes. It is a meticulous course of, demanding precision and a spotlight to element at every stage. The next steps Artikel the whole process, from preliminary preparation to remaining knowledge recording.
- Preparation of the Equipment: Completely clear the sand cone equipment, guaranteeing the cone is free from any particles or overseas materials. Fastidiously stage the equipment to take care of accuracy throughout the check. Make sure the sand used within the cone is clear, dry, and conforms to the prescribed grain measurement distribution. Confirm the calibration of the sand cone and any auxiliary measuring instruments.
- Preparation of the Pattern: Fastidiously excavate the soil pattern utilizing a pre-determined technique. Make sure the pattern represents the supposed soil kind and placement. Take precautions to reduce disturbance to the encompassing soil. Place the excavated pattern in a container for later evaluation.
- Placement of the Sand Cone: Fastidiously place the sand cone equipment over the soil pattern. This step ensures that the soil pattern is totally enclosed throughout the sand cone’s space of affect. This ensures that every one the soil is captured and precisely measured.
- Sand Pouring: Slowly and steadily pour the sand into the cone. This managed pouring ensures the sand fills the cone uniformly and doesn’t create air pockets. The pour must be steady, stopping any important pauses. The pouring must be carried out till the cone’s aperture is absolutely crammed.
- Quantity Measurement: Fastidiously document the quantity of sand poured into the cone utilizing the calibrated measuring cylinder. This step includes exact measurement, guaranteeing correct knowledge acquisition. File this quantity for later calculations.
- Pattern Extraction: Take away the cone from the pattern. Make sure the cone is fastidiously eliminated to stop any lack of soil. This stage ensures that all the pattern has been extracted for correct measurement.
- Knowledge Recording: File the preliminary and remaining ranges of the sand cone. File all related knowledge factors, together with the date, time, location, and different pertinent data. This contains the burden of the extracted pattern, the quantity of sand poured, and some other mandatory measurements. Guarantee correct knowledge entry.
Correct Measurement of Soil Quantity
An important side of the sand cone check is the correct measurement of the quantity of soil extracted. This necessitates precision within the sand pouring and the quantity recording course of.
- Calibration: Make sure the sand cone equipment and the measuring cylinder are calibrated appropriately. Calibration verifies the accuracy of the equipment.
- Managed Pouring: A constant pouring charge ensures the sand fills the cone with none air pockets. A constant pouring charge prevents important fluctuations within the sand quantity.
- Exact Quantity Studying: Precisely learn the quantity of sand poured from the measuring cylinder. Fastidiously document the quantity on the cone’s aperture.
Purposes of Sand Cone Take a look at Tools
The sand cone check, a seemingly easy but highly effective method, performs a vital position in geotechnical engineering. It is a versatile device for figuring out the quantity of voids in soil samples, a key parameter for understanding soil properties and habits. This understanding is important for a variety of tasks, from setting up secure foundations to assessing the suitability of a website for a brand new constructing.This technique is particularly helpful for rapidly and precisely measuring the quantity of soil.
Its ease of use and comparatively low price make it a gorgeous alternative for area investigations. Its simplicity contrasts sharply with the complexity of another soil testing strategies, making it a sensible answer for a lot of conditions.
Soil Mechanics Purposes
The sand cone check is a basic process in soil mechanics. It is used to find out the quantity of voids in a soil pattern. This data is crucial for numerous calculations and analyses associated to soil properties. As an illustration, the quantity of voids straight influences the soil’s density, compressibility, and permeability.
- Figuring out Soil Density: The check helps decide the in-situ dry density of a soil pattern, offering essential insights into the soil’s compactness and stability. This knowledge is important in tasks requiring secure foundations, like constructing dams or bridges. The outcomes of those exams are straight integrated into the design calculations for the mission.
- Evaluating Compaction High quality: Evaluating the in-situ dry density to the specified density offers a measure of the compaction high quality achieved throughout development. This permits engineers to evaluate whether or not the compaction course of was efficient and whether or not further compaction is required to satisfy mission specs. For instance, in freeway development, guaranteeing correct compaction is important to stop future settlement and keep the highway’s integrity.
Correct compaction is paramount for the longevity of the highway.
- Estimating Void Ratio: The check facilitates the calculation of the void ratio, a vital parameter in evaluating the soil’s habits below stress and pressure. The void ratio is straight associated to the porosity of the soil, influencing its potential to empty water and its total stability. This data is important for assessing the suitability of a website for numerous development tasks.
Geotechnical Engineering Purposes
The sand cone check is broadly utilized in geotechnical engineering tasks. It performs a pivotal position in assessing the suitability of a website for numerous constructions. This includes figuring out the quantity of voids, which helps predict the habits of the soil below completely different hundreds and circumstances.
- Basis Design: In designing foundations, engineers use the check outcomes to grasp the soil’s bearing capability and settlement potential. This ensures that the muse can help the construction’s weight with out extreme settlement or failure. As an illustration, within the development of skyscrapers, the soundness of the muse is paramount to the construction’s security and longevity.
- Slope Stability Evaluation: The sand cone check assists in evaluating the soundness of slopes. Understanding the quantity of voids helps predict the chance of slope failure. That is essential in tasks involving earth dams or embankments, the place the soundness of the slope is crucial for stopping landslides.
- Embankment Design: In embankment development, the check aids in figuring out the required compaction effort to realize the specified density. The amount of voids within the embankment soil is straight associated to its stability and talent to help hundreds. For instance, the development of an embankment for a railway line requires cautious consideration of soil properties to make sure the soundness of the embankment.
Figuring out Quantity of Voids
The sand cone check is a simple technique for figuring out the quantity of voids in a soil pattern. The tactic includes fastidiously filling a calibrated sand cone with soil from the pattern and measuring the quantity of sand that has been displaced. This offers a direct measure of the quantity of voids.
The amount of voids is calculated by subtracting the quantity of the strong soil from the entire quantity of the pattern.
- Precision and Accuracy: The check gives comparatively excessive precision in figuring out the quantity of voids in a soil pattern. That is essential in eventualities the place exact measurements are important for correct evaluation. The check’s simplicity and ease of use make it an excellent technique for area investigations.
- Discipline Purposes: The sand cone check is commonly utilized in area investigations to find out the in-situ quantity of voids in soil samples. This strategy is especially invaluable when fast evaluation of soil properties is required.
Examples of Helpful Purposes
The sand cone check is broadly relevant in numerous engineering tasks.
- Freeway development: Figuring out the compaction high quality of subgrade supplies is essential for highway stability and longevity. The sand cone check offers important knowledge for this course of.
- Dam development: Evaluating the soundness of the dam’s basis and embankment is crucial. The sand cone check aids on this evaluation.
- Airport development: The check aids in evaluating the soundness of the soil beneath the runway and taxiways. Guaranteeing the soundness of the soil below these constructions is important for the sleek operation of the airport.
Components Affecting Sand Cone Take a look at Outcomes
The sand cone check, a invaluable device for figuring out soil quantity, is delicate to varied elements. Understanding these influences is essential for acquiring correct and dependable outcomes, enabling knowledgeable selections in geotechnical engineering. Precisely decoding these outcomes permits engineers to design secure and purposeful constructions.The precision of the sand cone check is closely reliant on the meticulous execution of the process and the cautious consideration of exterior elements that may have an effect on the measurement of soil quantity.
These elements vary from the traits of the soil itself to the gear used and the environmental circumstances.
Potential Sources of Error
The sand cone check, like several laboratory process, is prone to errors. Human error, equivalent to improper calibration of the sand cone or inaccurate measurements of the sand quantity, can result in important discrepancies within the outcomes. Environmental circumstances, together with temperature fluctuations and variations in atmospheric stress, may also affect the check’s final result. Utilizing improperly calibrated gear or using incorrect procedures may also have an effect on the accuracy of the outcomes.
Moreover, improper dealing with of the soil pattern previous to testing can result in inaccurate outcomes.
Affect of Completely different Soil Sorts
Completely different soil sorts exhibit various levels of compaction and particle measurement distribution. These traits straight affect the quantity of sand required to fill the voids within the soil pattern. Superb-grained soils, with their smaller particles and better tendency to compact, would possibly require extra sand to fill the voids. Coarse-grained soils, then again, with bigger particles and a looser construction, will usually require much less sand to fill the voids.
These variations should be taken into consideration to acquire correct and significant outcomes. As an illustration, a sandy soil may have a unique void ratio in comparison with a clayey soil.
Affect of Sand Cone Design Variations
The design of the sand cone considerably impacts the accuracy of the check. The cone’s form, the fabric used for its development, and the consistency of the sand used all play a job. Variations within the cone’s dimensions can alter the quantity of sand that may be poured. Inaccurate measurement of the sand poured, or inconsistent pouring methods, may also result in errors.
Utilizing a cone that’s not correctly calibrated or isn’t persistently maintained may also introduce error into the check. Subsequently, it is very important make the most of a sand cone that meets the mandatory requirements and has been calibrated for accuracy.
Impact of Moisture Content material
Moisture content material is a big issue affecting the check outcomes. Water within the soil can alter its density and quantity, making the outcomes inaccurate. Moist soils usually exhibit a better quantity, necessitating extra sand to fill the voids. Conversely, dry soils may have a decrease quantity and require much less sand. Moreover, moisture content material can have an effect on the consistency of the soil pattern, which can have an effect on the accuracy of the check outcomes.
The check process ought to at all times account for the soil’s moisture content material.
Security Precautions for Sand Cone Testing
Sand cone testing, whereas a invaluable method for figuring out soil properties, requires meticulous consideration to security. Correct procedures and consciousness of potential hazards are essential for a profitable and incident-free testing course of. A protected work setting not solely protects personnel but additionally ensures the reliability of the collected knowledge.Correct security precautions are paramount throughout sand cone testing, because the gear and procedures contain potential dangers.
Fastidiously following the Artikeld security measures can reduce the probabilities of accidents, defending the gear, personnel, and the integrity of the outcomes. Dealing with the sand cone equipment and the related supplies calls for respect for potential hazards and adherence to security protocols.
Dealing with the Sand Cone Equipment
Guaranteeing protected dealing with of the sand cone equipment is important. The sand cone itself, sometimes made of sturdy materials, must be dealt with with care to keep away from harm or unintended spillage. Examine the equipment for any pre-existing harm earlier than use. Examine the sand cone for cracks, dents, or some other indicators of harm that will compromise its structural integrity.
This meticulous inspection is a crucial first step in guaranteeing protected operation.
Personnel Security Measures
The well-being of personnel concerned within the sand cone testing course of is paramount. Eye safety, within the type of security glasses or goggles, must be worn always. This easy measure protects the eyes from potential flying particles or unintended splashes. Correct footwear can be mandatory to stop slips, journeys, or falls in a doubtlessly uneven or moist testing space.
Guaranteeing the testing space is well-lit can be vital to boost visibility. This measure minimizes the danger of mishaps.
Dealing with Sand and Different Supplies
The dealing with of sand and different supplies concerned within the sand cone check necessitates particular precautions. All the time use applicable protecting gear equivalent to gloves to keep away from pores and skin irritation or accidents from contact with the sand. Using applicable respiratory safety can be mandatory, particularly when dealing with contaminated or doubtlessly dangerous supplies. Correct disposal of supplies, just like the used sand, is essential.
Incorrect disposal practices can result in environmental hazards.
Testing Procedures and Tools Operation
Strict adherence to the established testing procedures is essential for security. Make sure the testing space is evident of obstructions to keep away from tripping hazards or collisions throughout the testing course of. Working the gear in accordance with the producer’s directions is important to keep away from malfunctions and accidents. Cautious monitoring of the gear throughout operation can be vital. Common checks for any indicators of surprising habits or malfunction are crucial to sustaining security.
Abstract of Security Measures
| Testing Course of Step | Security Precautions |
|---|---|
| Equipment Setup | Examine equipment for harm. Guarantee a transparent and well-lit working space. |
| Sand Dealing with | Use gloves and respiratory safety if mandatory. Deal with sand fastidiously to stop spills. |
| Testing Process | Observe the standardized process meticulously. Preserve a detailed watch on the equipment throughout operation. |
| Equipment Cleanup | Get rid of supplies appropriately. Make sure the testing space is clear and tidy. |
Knowledge Evaluation and Interpretation of Outcomes
Unveiling the secrets and techniques hidden throughout the sand! The sand cone check, a invaluable device for figuring out soil quantity and void ratio, hinges on meticulous knowledge recording and insightful interpretation. Understanding the outcomes empowers us to know the soil’s properties, guiding essential selections in development and engineering tasks.Understanding the uncooked knowledge collected from the sand cone check is vital to decoding the soil’s traits.
This knowledge evaluation permits us to find out essential parameters like quantity and void ratio, offering important insights into the soil’s habits.
Recording Knowledge
Cautious recording of measurements is prime to correct outcomes. This includes meticulous consideration to element in recording the preliminary and remaining weights of the sand cone and the burden of the soil pattern. The amount of the sand cone is usually recognized. The method of recording knowledge must be exact, guaranteeing correct reflection of the measurements.
Calculating Soil Quantity
Figuring out the soil quantity is a simple calculation. The distinction between the preliminary and remaining weights of the sand cone is essential. The amount of sand that has been displaced by the soil pattern represents the soil’s quantity. A typical system for this calculation is:
Soil Quantity = (Preliminary Weight – Closing Weight) / Sand Density
Remembering the density of the sand used is paramount for exact calculations.
Calculating Void Ratio
The void ratio, a crucial parameter, quantifies the proportion of voids throughout the soil. This ratio is calculated by dividing the quantity of voids by the quantity of solids.
Void Ratio = (Quantity of Voids) / (Quantity of Solids)
Understanding the soil quantity and the entire quantity of the soil pattern permits us to compute the quantity of voids.
Deciphering Ends in Relation to Soil Properties
The sand cone check offers insights into the soil’s habits. The void ratio, together with different exams, can illuminate the soil’s compaction, permeability, and total stability.
Instance Knowledge Interpretation
| Pattern ID | Preliminary Sand Cone Weight (g) | Closing Sand Cone Weight (g) | Sand Density (g/cm³) | Soil Weight (g) | Soil Quantity (cm³) | Void Ratio | Soil Description |
|---|---|---|---|---|---|---|---|
| 1 | 100 | 80 | 1.6 | 20 | 12.5 | 0.75 | Free Sand |
| 2 | 100 | 90 | 1.6 | 10 | 6.25 | 0.50 | Medium Dense Sand |
| 3 | 100 | 95 | 1.6 | 5 | 3.125 | 0.375 | Dense Sand |
These examples illustrate the correlation between the void ratio and the soil’s density. The void ratio values (0.75, 0.50, and 0.375) assist to categorise the soil samples (unfastened, medium dense, and dense) by way of their density.
Comparability with Different Testing Strategies
The sand cone technique, a time-tested method for soil quantity willpower, gives a sensible and comparatively simple strategy. Nonetheless, understanding its strengths and weaknesses compared to different strategies is essential for choosing probably the most applicable method for a given mission. Understanding when to make use of the sand cone technique, and when to decide on one other strategy, ensures effectivity and reliability in soil evaluation.The sand cone check offers a direct measurement of the quantity of soil.
This differs from different strategies, a few of which depend on oblique measurements or assumptions. The precision of the sand cone check, when carried out appropriately, is critical. Components such because the consistency of the sand and the accuracy of the quantity measurement are essential for acquiring dependable outcomes. Understanding the comparative benefits and downsides, alongside the circumstances that favor its use, permits knowledgeable decision-making in soil engineering tasks.
Various Strategies for Soil Quantity Measurement
Numerous strategies exist for figuring out soil quantity, every with its personal set of benefits and downsides. These various methods usually contain completely different ideas and approaches, impacting their suitability for particular soil sorts and mission necessities.
Comparability Desk: Sand Cone vs. Different Strategies
| Methodology | Accuracy | Price | Time Required | Suitability |
|---|---|---|---|---|
| Sand Cone Take a look at | Usually good, relying on method and sand high quality. | Reasonable, requiring specialised gear. | Reasonable, taking a couple of minutes to an hour, relying on the soil kind and check pattern measurement. | Appropriate for comparatively small samples, unfastened soils, and conditions the place a direct measurement of the quantity is desired. |
| Water Displacement Methodology | Excessive accuracy for uniform-sized samples, however may be affected by soil traits. | Low, requiring fundamental gear. | Quick, sometimes taking lower than Half-hour. | Appropriate for measuring the quantity of compacted soils, however will not be correct for extremely variable soils. |
| Nuclear Density Gauge | Excessive accuracy, offering density and quantity concurrently. | Excessive, specialised gear is pricey. | Quick, outcomes are obtained in minutes. | Appropriate for big areas and for speedy measurement of soil properties, particularly in conditions the place the soil quantity is massive and requires quick evaluation. |
| Displacement Pycnometer | Excessive accuracy, providing exact measurements. | Excessive, specialised gear is required. | Reasonable, taking about 15-Half-hour, relying on the check pattern. | Appropriate for exact quantity willpower in laboratory settings. |
Conditions Favoring the Sand Cone Take a look at
The sand cone technique excels in sure conditions, usually involving particular soil traits and mission necessities.
- The sand cone check is well-suited for conditions requiring a direct measurement of soil quantity in comparatively small samples. The tactic’s potential to straight measure the soil quantity makes it a most popular alternative when excessive precision is required in laboratory or area settings.
- The tactic works properly for unfastened soils, the place the soil particles should not tightly compacted. The sand’s potential to fill the voids throughout the soil pattern permits for a direct and dependable quantity measurement.
- The sand cone check proves to be advantageous when a speedy however fairly correct measurement is required. The process, whereas not instantaneous, is usually faster than another strategies.
Benefits of the Sand Cone Take a look at
The sand cone check gives a number of benefits over different methods. These benefits stem from its simple process and the direct measurement it offers.
- Simplicity and ease of use, making it accessible to a wider vary of customers.
- Comparatively low price in comparison with some superior methods.
- Direct measurement of soil quantity, minimizing oblique measurements and potential errors.
Disadvantages of the Sand Cone Take a look at
Whereas the sand cone check gives many advantages, it additionally has some limitations.
- Accuracy is contingent upon the standard of the sand and the precision of the gear.
- Time required for the check can fluctuate, relying on the pattern measurement and the soil kind.
- The check won’t be appropriate for extremely compacted soils, because the sand won’t absolutely penetrate the voids.
