compaction simulator: a novel device for pressure

Journal of Earth Science, Vol. 31, No. 5, p. 1045–1050, October 2020 ISSN 1674-487X Printed in China https://doi.org/10.1007/s12583-020-1334-6

Liu, Y. J., Ma, T., Chen, J., et al., 2020. Compaction Simulator: A Novel Device for Pressure Experiments of Subsurface Sediments. Journal of Earth Science, 31(5): 1045–1050. https://doi.org/10.1007/s12583-020-1334-6. http://en.earth-science.net

Compaction Simulator: A Novel Device for Pressure Experiments of Subsurface Sediments

Yanjun Liu 1, 2, Teng Ma *1, Juan Chen1, Ziqi Peng1

1. School of Environmental Studies, China University of Geosciences, Wuhan 430074, China 2. Earth Systems Science, Stanford University, Stanford 94305, USA

Yanjun Liu: https://orcid.org/0000-0002-3235-1070; Teng Ma: https://orcid.org/0000-0003-2827-9579 ABSTRACT: Increasing overburden pressure is a key factor that alters the chemical and physical properties of soils and sediments. However, limited information is presently available on how aquifer compression im-pacts water quality. We introduced a novel compaction device, which is composited of four parts, including pressure simulator reactor system (PSRS), gas-liquid separator (GLS), automatic collector (AC) and compo-site control system (CCS). We conducted experiments at various pressures to test the functionality and out-comes of the device. In general, this device can be used to examine changes in water chemistry associated with aquifer compression resulting from compaction (overburden pressure) or groundwater overdraft. KEY WORDS: instrument, clay, sediment, compaction.

0 INTRODUCTION Recognition of compaction on water chemistry remains

largely unknown. Unlocking this mystery will provide critical information on groundwater contamination, pollutant migration, mineralization and other related phenomena (Xiao et al., 2016; Lloret et al., 2003; Collin et al., 2002; Eugene and Shinn, 1983). Soil compaction is an especially important environmental prob-lem now which can be caused by agricultural machinery, but also some natural conditions without human or animal involvement (Beylich et al., 2010; Batey, 2009). And the sediments can be also compacted with burial depth by the increasing overburden pressure (Mondol et al., 2007; Audet, 1995). Amount of previous researches suggested that gravitational compaction was able to control the permeability and connection of gases (such as air, CO2 of respiration) and water in soils and sediments via the re-duction of porosity, the pore fluid pressure and mineral struc-tures (Dasgupta and Mukherjee, 2020; Liu et al., 2017; Ruser et al., 2006). In this regard, compaction is a key factor for altering the chemical and physical properties of soils and sediments.

Physical devices used to study compaction can be mainly divided into uniaxial, biaxial and triaxial categories according to the types of compressive stress. Early in 1986, Sandbaekken et al. (1986) introduced a high-stress uniaxial oedometer with the feature of a vertical effective stress, with three different heights, which could be placed with or without a chamber for back- pressuring. It was widely modified for investigating the compac-tion behavior and rock properties of various sands concerning the textural properties and mineralogical composition (Koochak *Corresponding author: [email protected] © China University of Geosciences (Wuhan) and Springer-Verlag GmbH Germany, Part of Springer Nature 2020 Manuscript received March 8, 2020. Manuscript accepted April 15, 2020.

Zadeh et al., 2016; Mondol et al., 2008, 2007), evaluating the vertical swelling pressure parameter (Langroudi and Yasrobi, 2013) and other numerous related researches. The first biaxial oedometer was mentioned by Bishop and Donald in 1961. Then there were several different designs that were presented (Alabdullah et al., 2009; Sivakumar et al., 2006; Ng et al., 2002; Yin, 2002; Toyota et al., 2001; Cui and Delage, 1996). Later, a biaxial device was designed to measure the axial stress and strain to account for hypoplastic constitutive impacts (Pincus et al., 1993). The triaxial compactor usually was applied for the super high-pressure strain (CRS) compression testing of soils and sed-iments (Muna and McCartneyb, 2015). Neveux et al. (2014) also proposed a triaxial device that was able to be used to simulate deeply buried reservoirs and record the results of stresses, fluid pressure, and strains in-situ.

Previous studies, and the properties of the compaction de-vices, have focused on the physical properties of soils and sedi-ments, including pore structure, densities and porosity, and a few studies also examine chemical reactions under super-high pres-sure (usually up to 50 MPa) (Nooraiepour et al., 2017; Fawad et al., 2011). Considerable information found that the porosity and water content, which had great variations in the initial period of compaction with a low pressure, were key factors for controlling the microbe and chemical reactions of soils and sediments (Rubol et al., 2013; Saha and Hossain, 2011; Zeglin et al., 2011). There is, however, lack of a specialized in-situ instruments for the experiments on the initial compaction of soils and sediments and especially resulting impacts on water chemistry. The re-search presented a novel compaction instrument with an auto collector and an analysis system which include analytical instru-ments; capable of measuring the chemistry of gases and liquids squeezed from sediment samples under the pressure. It was de-veloped to explore the chemistry of samples under the different pressures. This device was subject to a series of pressure tests to demonstrate its reliability, robustness and safety. According to

Yanjun Liu, Teng Ma, Juan Chen and Ziqi Peng

1046

the overburden pressure (Weller, 1959), we estimated the pres-sure at 20 m thick layers to be 0.6 MPa. Here we use pressure tests ramping to 0.6 MPa at different rates to illustrate impact on water and gas chemistry.

1 DEVICE DESIGN AND CONFIGURATION

The entire system is composited of four major parts charac-terized with their own special functions, including pressure sim-ulator reactor system (PSRS), gas-liquid separator (GLS), auto-matic collector (AC) and composite control system (CCS). They are connected with each other (as shown in Fig. 1) to realize the online monitor for the compaction experiments under a long time operation. PSRS, the core component of this device, is composed of a sampling chamber, pressure unit, heating cover and in-line sensor. The function of GLS is to separate the gases and the liq-uids flowing out of the PSRS. AC is able to split the separated gas and liquid, allowing them to then be measured in the con-necting analytical instruments. The control and data processing is performed by CCS.

Figure 2 presents the assembly diagram of two sets of the PSRS. According to the various purposes of the experiments, two sets of reaction chambers are made from two different ma-terials. The first chamber (Fig. 2a) is made from Hastelloy Alloy C-276 (HC Chamber), a kind of special alloy material which is able to resist high pressure, high temperature and corrosion (Leonard, 1969). The chamber are covered by heating jackets (designed as hollow cylinders of 98.00 cm (38.58 inch) high and 8.00 cm (3.15 inch) diameter). The heating jacket provides the temperature which is supported by a circulating temperature controller and determined by the characters of the media materi-als. Here, we choose the phenylmethyl silicone oil as the heating fluid which allows for a temperature range from -50 to 200 °C. A precise actuating motor combined with a long screw as the power system is used to drive a piston moving that increases the overburden pressure. The range of the pressure is from 0 to 15 000 kPa (0–15 MPa), and can be set with different rates of increase in pressure (i.e., 100 kPa per day, 100 kPa per hour, 100 kPa per min). With a height of 20 cm sampling cells, this cham-ber is able to study the changes of pore water and sediments at various depths. The sampling cells are vertically (in uniform ar-rangement) to facilitate fluid flow and sediments, and they are mounted to the chamber. Furthermore, the filters are equipped in outputs and their materials can be changed according to various types of samples. In order to add additional sources into the chambers during the pressurization process, a pressure injection unit (as shown in Fig. 2a) is used. During this process, the injec-tion pressure of additional sources should not be less than the pressure applied in the chamber. Therefore, water is pumped by a pressure pump into a piston column to provide pressure for the injection solutions. When the additional sources are gases, we can connect a gas valve to an air supply directly. And this part also can be used to collect the liquid samples from the top. For monitoring and recording the displacement of piston, a displace-ment sensor is placed on the top of the shaft attached to the pis-ton. There are two temperature sensors monitoring the center and the edge of samples and three pressure sensors monitoring the top and the bottom of solid and liquid samples.

The other chamber (as shown in Fig. 2b) made of Polyether ether ketone (PEEK) can be examined by the computed tomog-raphy (CT scan) without the pressure relief (O’Reilly et al., 2015; Rae et al., 2007). Different from the HC Chamber, the main function of this chamber is able to have CT scan, so the materials of its accessories must be non-metallic. In this cham-ber, we use a high quality actuating motor combined with a long screw and another piston chamber to provide the overburden pressure. The water in the piston chamber can be forced into the PEEK Chamber to give pressure on the samples. We can close the valve which is connected the piston chamber and the PEEK Chamber, and bring the whole PEEK Chamber with keep the overburden pressure to have the CT scan. Based on the some characters of the pressure methods on the two chambers, there are some differences between two sets of the pressure injection units. Its pressure unit can only add an extra channel to the piston chamber when the pressure of additional sources is same as its pressure on the samples (Fig. 1b), but the same pressure unit as shown in Fig. 1a is needed when the experiments need a greater pressure for additional sources. As for the sampling cells, the PEEK Chamber only has two sampling ports at bottom for col-lecting liquid and solid respectively. In addition, the sensors in this chamber is arranged to the HC Chamber.

The liquid squeezed from the samples is always a mixer with some gases. The design of gas-liquid system is based on gravity flow as illustrated in Fig. 3. It is also a simple piston sys-tem which can adjust the volume and pressure, according to wa-ter flow from the PSRS. The piston can be fastened by two pins on the top of the GLS, and is similar to a “sifter” full of small holes. The top Teflon film allows for gas but not liquid transmis-sion. In contrast, an alternate film attached at the bottom allows for fluid flow and collection. Two tubes are set in the piston. The longer one is used for supplying mixed gas-liquid from the PSRS, and the shorter one for retrieving the gas with connecting an extracting pump. In addition, micro-air pump connects with the shorter tube for collecting the gas and sending them into the gas chromatography (GC). A solenoid valve connects with the bottom tube to control.

Figure 1. Schematic diagram of the pressure testing device showing the four

primary components.


1047

Figure 2. Two configuration of PSRS. (a) A chamber made of HC-267, a pressure injection unit and circulating temperature controller; (b) a chamber made of

PEEK, a pressure injection unit and circulating temperature controller.


1048

As the key part of connecting the various analysis instru-ments, the schematic diagram of automatic collector is displayed in Fig. 4. Unlike a standard fraction collector, this AC have two mechanical arms for injection needles (designed for the outputs of PSRS or GLS) and sampling needles (designed for the inputs of various analysis instruments) separately. In the AC, two me-chanical arms able to moving in three directions (up and down, front and back, right and left) are set to make “collecting” and “taking” actions. “Collecting” makes the liquid flow into the sample bottles. The second arm can carry out the “taking” ac-tions for the analysis instruments.

Composite control system (CCS) is the “brain” of this de-vice and allows automated control and monitoring. It allows set-ting of temperature, pressure, temperature change rate, pressure change rate, displacement rate and other parameters, as well as data acquisition and processing. It is able to execute the data files (in excel format) and some line-graphics automatically. AC is also controlled by it and easily to be enforced the operations based on the experimental requirements.

Figure 3. Configuration of gas liquid system (GLS). The longer tube is con-

nected to PSRS. When mixed gas-liquid from PSRS flows into the GLS, the

solenoid valve is closed until micro-air pump extracts the gas out. The sole-

noid valve and the micro-gas pump can be set to open and close intermittently

based on the experiments demands. The liquid will flow into the next compo-

nent of the system.

Figure 4. Schematic view of the Automatic Collector. This sampling needle

is used to connect the analyze devices. The injection needle is used to collect

the liquid from different outputs.

2 MATERIALS AND METHODS To test the device, clayey sediments were collected from a

depth of 2 m below a rice paddy in Jianghan Plain. The water table of the rice paddy was below 1.1 m, and the collected sam-ples were soaked in the groundwater with an average initial wa-ter content around 40.1%. Before filled the chamber with the samples, they were air dried for several days, then ground and sieved through a 200-mesh screen to ensure homogeneity. Sedi-ments were added to the columns to a height of roughly 2 cm and then thoroughly compacted by a PMMA rod. This progress was repeated until the chamber was filled with the sediment-packed columns. After adding sediment, the plunger was placed at the surface of samples. Deionized water was then pumped into the chamber at a rate of 0.2 mL·min-1 from the bottom sampling cell. The water content of the samples was determined by two meth-ods. One was by calculating the mass of influent solutions and the total mass, the other was by mass differences of the samples before and after drying in an oven at 105 °C.

Our experiments represented three pressure modes: con-stant rate, acceleration rate and deceleration rate. We also in-cluded five different pressure rates: 0.02 MPa per 12 h, 0.04 MPa per 12 h, 0.06 MPa per 12 h, 0.04 MPa per 24 h, 0.04 MPa per 36 h, from 0.04 MPa per 12 h to 0.02 MPa per 12 h and from 0.04 MPa per 12 h to 0.06 MPa per 12 h. After preparing the samples as mentioned above, we input the final pressure and the pressure rate in the CCS. Then the flow rate, calculated by the liquid volumes from the PSRS at a certain time, could be ad-justed for realizing the online monitoring. After the tests above, we also carried out unilateral and bilateral drainage experiments to present an additional example of this device. Here, we col-lected liquid samples from the bottom sampling cells (unilateral drainage) and both the bottom and top (bilateral drainage), and measured their masses.

3 RESULTS 3.1 Accuracy

For testing the pressure accuracy, we carried out 14 pres-sure tests and calculated the difference between add-value and test-value. It was able to reach ±1.01‰. And we used the mixed N2-H2O samples to go through GLS for verifying its accuracy. The result showed 89.61% N2 can be collected from the GLS. The temperature accuracy was less than ±1% only on a higher moisture samples within the range 18.0 and 37.5 °C.

3.2 Operation Test

Table 1 showed the initial moisture and porosity data of the samples for the pressure tests. The maximum initial moisture of samples in five pressure modes is 39.76%, the minimum is

Table 1 Initial moisture and porosity data of samples on various

pressure modes

Pressure mode Initial moisture (%) Initial porosity (%)

0.04 MPa/12 h 39.61 62.13

0.04 MPa/24 h 39.28 61.75

0.04 MPa/36 h 39.76 62.51

0.04–0.02 MPa/12 h 39.61 62.13

0.04–0.06 MPa/12 h 38.92 62.51


1049

38.92%. And the initial porosity of that is around 62%. There were five tests carried out to test the pressure function. The errors between results tested by the pressure sensors and added values were within ±0.001 MPa. Figure 5 illustrates the relationship be-tween added pressure values and tested pressure values, and the slight errors might occur in a long experiment. Comparing the displacements of the five modes, the instruments could perform the changeable pressures during the experiments well. Addition-ally, we tested the functions of top and bottom sampling cells (Table 2). We chose 0.02 MPa per 12 h, 0.04 MPa per 12 h and 0.06 MPa per 12 h as the pressure rates. The fluids were effec-tively displaced from the top and bottom sampling cells. Inter-estingly, the water masses of unilateral groups were lower than the bilateral. More importantly, there were great differences be-tween the chemical results of the top and the bottom samples. 4 SUMMARY

We tested the pressure device at 0.6 MPa, but it is capable of extending to 15 MPa. The device is also able to perform ex-periments at varying temperature and vertical flow rates, with or without the pressure. The pressure injection coupling unit can be used as an input or sampling cell. And the functions on vertical flows supply the possibility for finding out the differences of the complicate reactions with kinds of external sources (e.g., solu-tions or gases). In addition, the PEEK chamber can help to ex-plore the change of pore size and pore structure of various solid samples (e.g., sand, clay, silt) or liquid samples under different pressures. Furthermore, with the auto sampling collector and computer controlling system, high-throughput sampling can eas-ily be accomplished by tight experimental control. In general, this device can be used for studying and solving some key issues on diverse areas including compaction, land subsidence, and hy-draulic engineering.

Table 2 Water mass results on three pressure modes

0.02 MPa/12 h 0.04 MPa/12 h 0.06 MPa/12 h

Unilateral Bilateral Unilateral Bilateral Unilateral Bilateral

Water mass (g) 1 941.81 2 208.42 2 100.66 2 483.91 2 073.9 2 565.33

Figure 5. Relationship between test pressure values and added pressure values.

ACKNOWLEDGMENTS The authors would like to thank the National Natural Sci-

ence Foundation of China (Nos. 41630318, 41521001) and the Wuhan Institute of Industrial Technology of Geological Re-sources & Environment for their financial supports. We appreci-ate some great advices provided by Prof. Guoli Zhu from Huazhong University of Science and Technology and Prof. Scott Fendorf from Stanford University. The final publication is avail-able at Springer via https://doi.org/10.1007/s12583-020-1334-6.

REFERENCES CITED

Alabdullah, J., Lins, Y., Schanz, T., 2009. Shear Strength of Unsaturated Sand

under Plane Strain Conditions. In: Buzzi, O., Fityus, S., Sheng, D., eds.,

Proc., 4th Asia-Pacific Conf. on Unsaturated Soils. Taylor & Francis,

London

Audet, D. M., 1995. Mathematical Modelling of Gravitational Compaction

and Clay Dehydration in Thick Sediment Layers. Geophysical Journal

International, 122(1): 283–298. https://doi.org/10.1111/j.1365-

246x.1995.tb03554.x

Batey, T., 2009. Soil Compaction and Soil Management––A Review. Soil

Use and Management, 25(4): 335–345. https://doi.org/10.1111/j.1475-

2743.2009.00236.x

Beylich, A., Oberholzer, H. R., Schrader, S., et al., 2010. Evaluation of Soil

Compaction Effects on Soil Biota and Soil Biological Processes in Soils.

Soil and Tillage Research, 109(2): 133–143.

https://doi.org/10.1016/j.still.2010.05.010

Bishop, A. W., Donald, I. B., 1961. The Experimental Study of Partly Satu-

rated Soil in the Triaxial Apparatus. Proceedings of the 5th International

Conference on Soil Mechanics and Foundation Engineering, July 17–22,

1961. Paris

Collin, F., Li, X. L., Radu, J. P., et al., 2002. Thermo-Hydro-Mechanical Cou-

pling in Clay Barriers. Engineering Geology, 64(2/3): 179–193.

https://doi.org/10.1016/s0013-7952(01)00124-7

Cui, Y. J., Delage, P., 1996. Yielding and Plastic Behaviour of an Unsaturated

Compacted Silt. Géotechnique, 46(2): 291–311.

https://doi.org/10.1680/geot.1996.46.2.291

Dasgupta, T., Mukherjee, S., 2020. Compaction of Sediments and Different

Compaction Models. In: Dasgupta, T., Mukherjee, S., eds. Sediment

Compaction and Applications in Petroleum Geoscience. Springer,

Switzerland

Eugene, A., Shinn, D. M. R., 1983. Mechanical and Chemical Compaction in

Fine-Grained Shallow-Water Limestones. SEPM Journal of Sedimen-

tary Research, 53(2): 595–618. https://doi.org/10.1306/212f8242-2b24-

11d7-8648000102c1865d

Fawad, M., Mondol, N. H., Jahren, J., et al., 2011. Mechanical Compaction

and Ultrasonic Velocity of Sands with Different Texture and Mineralog-

ical Composition. Geophysical Prospecting, 59(4): 697–720.

https://doi.org/10.1111/j.1365-2478.2011.00951.x

Koochak Zadeh, M., Mondol, N. H., Jahren, J., et al., 2016. Experimental

Mechanical Compaction of Sands and Sand-Clay Mixtures: A Study to

Investigate Evolution of Rock Properties with Full Control on Mineral-

ogy and Rock Texture. Geophysical Prospecting, 64(4): 915–941.

https://doi.org/10.1111/1365-2478.12399

Langroudi, A. A., Yasrobi, S. S., 2013. Drainage Controlled Uniaxial Swelling

Cell. Proceedings of the Institution of Civil Engineers––Geotechnical En-

gineering, 166(4): 357–364. https://doi.org/10.1680/geng.9.00017

Leonard, R. B., 1969. Thermal Stability of Hastelloy Alloy C-276. Corrosion,

25(5): 222–232. https://doi.org/10.5006/0010-9312-25.5.222


1050

Liu, Y. J., Ma, T., Du, Y., 2017. Compaction of Muddy Sediment and Its

Significance to Groundwater Chemistry. Procedia Earth and Planetary

Science, 17: 392–395. https://doi.org/10.1016/j.proeps.2016.12.099

Lloret, A., Villar, M. V., Sánchez, M., et al., 2003. Mechanical Behaviour of

Heavily Compacted Bentonite under High Suction Changes. Géotech-

nique, 53(1): 27–40. https://doi.org/10.1680/geot.2003.53.1.27

Mondol, N. H., Bjørlykke, K., Jahren, J., 2008. Experimental Compaction of

Clays: Relationship between Permeability and Petrophysical Properties

in Mudstones. Petroleum Geoscience, 14(4): 319–337.

https://doi.org/10.1144/1354-079308-773

Mondol, N. H., Bjørlykke, K., Jahren, J., et al., 2007. Experimental Mechan-

ical Compaction of Clay Mineral Aggregates—Changes in Physical

Properties of Mudstones during Burial. Marine and Petroleum Geology,

24(5): 289–311. https://doi.org/10.1016/j.marpetgeo.2007.03.006

Muna, W., McCartneyb, J. S., 2015. Rate Effects in Constant Rate of Strain

Compression Tests on Unsaturated Soils to High Pressures. PanAmeri-

can Conference on Soil Mechanics and Geotechnical Engineering, No-

vember 15–18, 2015. Buenos Aires

Neveux, L., Grgic, D., Carpentier, C., et al., 2014. Experimental Simulation

of Chemomechanical Processes during Deep Burial Diagenesis of Car-

bonate Rocks. Journal of Geophysical Research: Solid Earth, 119(2):

984–1007. https://doi.org/10.1002/2013jb010516

Ng, C. W. W., Zhan, L. T., Cui, Y. J., 2002. A New Simple System for Meas-

uring Volume Changes in Unsaturated Soils. Canadian Geotechnical

Journal, 39(3): 757–764. https://doi.org/10.1139/t02-015

Nooraiepour, M., Mondol, N. H., Hellevang, H., et al., 2017. Experimental

Mechanical Compaction of Reconstituted Shale and Mudstone Aggre-

gates: Investigation of Petrophysical and Acoustic Properties of SW Bar-

ents Sea Cap Rock Sequences. Marine and Petroleum Geology, 80: 265–

292. https://doi.org/10.1016/j.marpetgeo.2016.12.003

O’Reilly, E. B., Barnett, S., Madden, C., et al., 2015. Computed-Tomography

Modeled Polyether Ether Ketone (PEEK) Implants in Revision Cranio-

plasty. Journal of Plastic, Reconstructive & Aesthetic Surgery, 68(3):

329–338. https://doi.org/10.1016/j.bjps.2014.11.001

Pincus, H., Kolymbas, D., Bauer, E., 1993. Soft Oedometer—A New Testing

Device and Its Application for the Calibration of Hypoplastic Constitu-

tive Laws. Geotechnical Testing Journal, 16(2): 263–270.

https://doi.org/10.1520/gtj10044j

Rae, P. J., Brown, E. N., Orler, E. B., 2007. The Mechanical Properties of

Poly (Ether-Ether-Ketone) (PEEK) with Emphasis on the Large

Compressive Strain Response. Polymer, 48(2): 598–615.

https://doi.org/10.1016/j.polymer.2006.11.032

Rubol, S., Manzoni, S., Bellin, A., et al., 2013. Modeling Soil Moisture and

Oxygen Effects on Soil Biogeochemical Cycles Including Dissimilatory

Nitrate Reduction to Ammonium (DNRA). Advances in Water Re-

sources, 62: 106–124. https://doi.org/10.1016/j.advwatres.2013.09.016

Ruser, R., Flessa, H., Russow, R., et al., 2006. Emission of N2O, N2 and CO2

from Soil Fertilized with Nitrate: Effect of Compaction, Soil Moisture

and Rewetting. Soil Biology and Biochemistry, 38(2): 263–274.

https://doi.org/10.1016/j.soilbio.2005.05.005

Saha, P. K., Hossain, M. D., 2011. Assessment of Heavy Metal Contamina-

tion and Sediment Quality in the Buriganga River, Bangladesh. In: 2011

2nd International Conference on Environmental Science and Technol-

ogy, February 26–28, 2011. IACSIT Press, Singapore

Sandbaekken, G., Berre, T., Lacasse, S., 1986. Oedometer Testing at the Nor-

wegian Geotechnical Institute. In: Yong, R., Townsend, F., eds., Con-

solidation of Soils: Testing and Evaluation. ASTM International, West

Conshohocken

Sivakumar, R., Sivakumar, V., Blatz, J., et al., 2006. Twin-Cell Stress Path

Apparatus for Testing Unsaturated Soils. Geotechnical Testing Journal,

29(2): 175–179. https://doi.org/10.1520/gtj14014

Toyota, H., Sakai, N., Nishimura, T., 2001. Effects of Stress History Due to

Unsaturation and Drainage Condition on Shear Properties of Unsatu-

rated Cohesive Soil. Soils and Foundations, 41(1): 13–24.

https://doi.org/10.3208/sandf.41.13

Weller, J. M., 1959. Compaction of Sediments. AAPG Bulletin, 43(2): 273–

310

Xiao, C., Ma, T., Du, Y., et al., 2016. Arsenic Releasing Characteristics dur-

ing the Compaction of Muddy Sediments. Environmental Science: Pro-

cesses & Impacts, 18(10): 1297–1304.

https://doi.org/10.1039/c6em00343e

Yin, J. H., 2002. A New Double Cell Triaxial System for Continuous Meas-

urement of Volume Changes of an Unsaturated or Saturated Soil Speci-

men in Triaxial Testing. Chinese Journal of Geotechnical Engineering,

24(5): 552–555 (in Chinese with English Abstract)

Zeglin, L. H., Dahm, C. N., Barrett, J. E., et al., 2010. Bacterial Community

Structure along Moisture Gradients in the Parafluvial Sediments of Two

Ephemeral Desert Streams. Microbial Ecology, 61(3): 543–556.

https://doi.org/10.1007/s00248-010-9782-7

compaction simulator: a novel device for pressure

Documents