Sandy Layers Research Articles

Distinction and grain-size characteristics of intertidal heterolithic deposits in the middle Qiantang Estuary (East China Sea)

The routine sampling procedure for grain-size analysis of intertidal heterolithic deposits runs a high risk of inadvertent mixing of two or more different sedimentation units, which would consequently complicate data interpretation. Traditionally, sedimentologists pay less attention to muddy layers due to a lack of internal structures, although the grain-size populations of such layers should encode more information on fine-mud flocculation processes than sandy layers. In this paper, individual muddy and sandy layers of nine short cores from the Da-Jian-Shan tidal flats of the middle Qiantang Estuary in the East China Sea, which experiences tidal bores, were sampled separately for grain-size analysis. A core taken at Huang-Jia-Yan from the lower estuary, not affected by tidal bores, served for comparison. A curve-fitting method was employed to decompose each grain-size distribution into two Gaussian populations. Cumulative plots indicate that intertidal sediments are mostly dispersed as intermittent and uniform suspension loads, traction loads being absent or very subordinate. This is conceivably linked to flows agitated by tidal bores, and to the highly dynamic nature of fine sand and coarse silt particles. Selective transport and deposition have produced three distinct sedimentation units, namely, tidal-bore deposits, tidal sandy deposits, and tidal muddy deposits. These can also be discriminated on bivariate plots of any two textural parameters. Shoreward attenuation of tidal flows is reflected in the gradual fining and thinning of sandy layers from lower-flat massive sands, through middle-flat hybrid deposits (alternations of massive sands and tidal rhythmites), to upper-flat tidal rhythmites. This gradient is also well represented in slightly decreasing (increasing) sorting and decreasing (increasing) proportions of the coarser (finer) hydraulic populations in the muddy layers. Although no corresponding trends are discernible in the hydraulic populations of the sandy layers, these can be distinguished on the basis of characteristic sedimentary structures. The floc limit and floc volume fraction, estimated from the modes and proportions of the finer hydraulic populations, are 8~10 μm (16 μm) and on average 41.73% (26.41%) for muddy (sandy) layers, respectively. The most plausible explanation is that the floc limit sensitively responds to subtle changes in the suspended sediment composition and the ambient hydraulic and hydrochemical settings. In comparison, the Huang-Jia-Yan core features blurred bedding and higher contents of fine mud and flocs, these being consistent with the weaker energy on the upper tidal flat of the lower estuary where neither tidal bores nor bigger waves occur.

DEM simulation of reverse faulting through sands with the aid of GPU computing

This paper presents the results of analyses of a Discrete Element Methodology (DEM) developed to study reverse faulting through sandy layers, considering the inherent ability of DEM to model strain localization phenomena in granular soils; the paper emphasizes on engineering significances of the results. An efficient DEM code is implemented on Graphic Processor Unit (GPU) using CUDA architecture in order to reduce significantly the computation effort of present DEM simulations. The results of sensitivity analyses show that the average inclinations of the reverse fault ruptures increase by increasing both fault dip angle and soil ductility, due to the variations of the maximum principle strain directions and dilation angles along the fault ruptures. This causes that the corresponding fault ruptures outcrop the ground surface at nearer distances from the projection of the fault trace in the bedrock on the ground surface. In addition, the results indicate that the fault ruptures in denser sand create higher gradients on the ground surface at outcropping locations compared with looser sand, causing more serious damage to adjacent structures. Moreover, the minimum bedrock displacement required for the rupture to reach the ground surface is evaluated adopting an internal energy criterion, being proportional to the soil ductility. In addition, the results show that the limits of distortion zones on the ground surface shift generally toward the hanging wall by increasing the fault dip angle.

On torsional surface wave in dry sandy crust laid over an inhomogeneous half space

An in-depth investigation has been carried out for the propagation of torsional surface waves in a dry sandy layer over an inhomogeneous half space. Both medium are assumed to be under compressive initial stress. The inhomogeneities that arise due to slow variation in rigidity and density in the lower half space is taken as an arbitrary function of depth. Using WKB approximation a closed form dispersion relation of torsional surface wave in the sandy layer has been formulated in terms of the arbitrary bounded functions. This dispersion equation is further employed to study the polynomial and exponential variation in rigidity and density of the half-space. An extensive analysis is carried out through numerical computation to explore the effect of inhomogeneity, initial stress, sandiness and thickness of the layer on the phase velocity of the torsional surface waves. The analysis of dispersion equation manifests the decline of phase velocity in the presence of sandy parameter as well as by increase in thickness of the sandy layer. The results further indicate that the initial stress of both the medium and the inhomogeneity of the half space affect the wave velocity significantly.

Influence of multi-layered soil formation on shield tunnel lining behavior

The recent development of larger shield-driven tunnels has for consequence that the tunnel face consists more frequently of multi-layered formations. However, most tunnel designs are still currently conducted in the homogeneous soil condition. In this study, a series of 1-g plane model tests and FEM analyses were carried out to investigate the influence of the layered soils in terms of their relative stiffness and thickness on the lining behavior (i.e. inner force and convergence). The numerical results were found to agree reasonably well with the results obtained from the model tests. For multi-layered formation, a linear increase of the relative thickness of the sandy layer could reduce non-linearly the magnitude of both the moment and the convergence. The distributions of the bending moment and of the convergence along the tunnel perimeter were found to be strongly dependent on the relative stiffness of the layered formations. However, the multi-layered condition has little effect on the thrust force under the condition of this test. In view of these results, some discussions on the applicability of the widely used homogenized design model for the multi-layered soil condition are finally presented.

Applicability of 'Gel-Push' sampling technique for sandy layer

Applicability of 'Gel-Push' sampling technique for sandy layer

東日本大震災および既往地震による液状化と沖積層分布

The 2011 off the Pacific coast of Tohoku Earthquake liquefied large areas of the Kanto region. At the reclaimed land of Urayasu and Mihama, Chiba prefecture, liquefaction tended to concentrate in sandy land-fill layers covering thick alluvium. Alluvial plains along the lower reaches are identified as depositional surfaces of the coastal prism (CP). The CP is sandwiched between the present and the last glacial river-profiles. In Japan, the last glacial rivers developed basal gravel layers (BG) along the bottom of the CP. A thick CP with BG lengthens the secondary seismic wave period and its duration because of a slow s-wave velocity and multi-reflection, resulting in increased internal water pressure and liquefaction of the upper sandy layer of the CP. Historic liquefaction sites show close relations with the distribution of the CP. Subduction-zone large earthquakes caused repeated liquefaction in an alluvial plain where the CP was more than 30 m thick. The inland limit of the liquefaction area roughly coincides with the upstream edge of the CP. The three largest rivers in the Kanto regionof Kinu River, Ara River, and Naka River (Furutone River) have the longest CP in Japan. As a result, the Great East Japan Earthquake liquefied large areas of the Kanto region. The Earthquake also liquefied inland basins such as the Koriyama basin with late Quaternary lacustrine sediments. This demonstrates that a mega-thrust earthquake has the potential to liquefy inland sediment-fill basins beyond the inland limit of the CP.

Correlation Analysis of Liquefaction Characteristic Parameters with Liquefaction Based on Real Testing Data

Through collecting real liquefaction in-situ data available worldwide, the correlations of influencing characteristics parameters such as PGA, water table depth, buried depth of sandy layer, SPT counts and shear wave velocity with respect to liquefaction were analyzed by means of Pearson correlation method. The correlative performance of the characteristic parameters with liquefaction was comparatively analyzed under conditions of varying buried depths, water tables and seismic intensities. The real correlations of the characteristic parameters with liquefaction were obtained corresponding to real dynamic loading, real buried condition and in-situ testing data. The analytical results show that water table, buried depth of sandy layer, SPT and shear wave velocity keep negative correlations with respect to liquefaction while correlation of PGA with liquefaction was positive. The correlations of buried depth of sandy layer, SPT were remarkable while the correlations of water table, shear wave velocity were weak. The correlation coefficient of SPT was the largest, followed by buried depth of sandy layer, PGA and water table; and the correlation coefficient of shear wave velocity was the smallest. The results presented herein can be used for updating the liquefaction evaluation methods in the codes.

Practical slip circle method of slices for calculation of bearing capacity factors

The slip circle method of slices is commonly used in the analyses of slope stability and bearing capacity for multi-layered ground. However, in the case of ground consisting of horizontal sandy layer, it is known that modified Fellenius׳ method tends to underestimate the factor of safety, while simplified Bishop׳s method tends to overestimate the factor of safety. In this study, a new slip circle method was proposed for the purpose of improving the accuracy of the analysis for a ground consisting of sand and clay layers. In the proposed method, β of the ratio of inter-slice shear force to inter-slice normal force i.e tan(βαi) is assumed constant as 0.25 for all slices. This is named as circle bearing capacity factor (CBCF) method. It was found that the bearing capacity factors, Nc, Nq, and Nγ calculated for shallow foundation on horizontal ground from CBCF method agreed well with that obtained from the plastic solution. The back-analyses carried out for a few case studies on the stability of slopes on earth structures found in sand and clay layers showed that the factor of safety calculated from CBCF method explains the actual performance of earth structures well. The proposed CBCF method proves it reliability in calculating bearing capacity for shallow foundations. This was achieved from the results obtained from centrifugal model test, which were carried out for dense sand layer overlying soft clay with various conditions by Okamura et al. (1998). It was examined that the factor of safety calculated for the stability of slopes from CBCF method can explain the actual performance of geotechnical structures constructed on ground consisting of sand and clay layers.

Lithological discontinuities in Podzols developed from sandstone cover beds in the Stolowe Mountains (Poland)

Podzols developed within so-called cover beds were examined on a slope built of Cretaceous sandstones in SW-Poland. Their typical feature is an easily recognizable stratification of regolith, evidenced in the dichotomy of soil texture and dense subsoil. Heterogeneity of soil profiles is manifested in vertically differentiated sequence: (1) dense, skeletal and massive layer, comprising usually Bs and BC horizons, sometimes Bhs/Bh horizons with strong platy structure is overlain by (2) the uppermost, relatively young layer, consisting of loose sandy material, bearing single coarse fragments of a less weathered sandstone, hosting AE, E and partially Bh horizons. This remarkable layering of slope sediments caused a distinctive lithological discontinuity at the boundary of E and B horizons, evidenced by the differences in: (i) rock fragments' content, (ii) degree of rock clast weathering, (iii) distribution of highly resistant minerals, and (iv) fluctuation of silt and sand fractions within profiles. Lithological discontinuity influences both the lateral podzolization, and the thickness and depth of albic and spodic horizons along the slope catena. Regarding the temporal order, the lowermost layer was influenced by periglacial conditions at before the Boreal; presumably as the surface layer (high score of pollen grains). The age of surficial sandy layer (based on pollen record) could be established at Subatlantic and correlated with forest cutting and intensive surface erosion (charcoal dating: 960+/−30calBP). Neither layers that originated from the eolian processes were distinguished nor any admixture of allochthonous material was found, therefore “typical” middle and upper periglacial cover-beds are not present in this sequence. In any case, Podzols that were formed from the slope sediments in the Stolowe Mountains are polygenetic and of the Holocene age.

Late Palaeolithic settlement pattern in palaeogeographical context of the river valleys in the Koło Basin (Central Poland)

The palaeogeography of the mid-Warta River valley in the Koło Basin in the Alleröd and Younger Dryas periods is well recognised. Record of subfossil trees is evidence of the existence of the riparian pine-birch forest in the valley floor in the Alleröd/Younger Dryas transition and in the early Younger Dryas. In the late Younger Dryas, the flood activity increased, which resulted in covering the valley floor with a thick layer of sandy and silty sandy overbank alluvia. Traces of settlement of people of only one archaeological culture dated to the Late Palaeolithic are recorded in the Koło Basin – i.e. the Tanged Point Complex, called in Polish territories the Sviderian Culture. The sites are camp sites remnants of hunter–gathering groups of the Alleröd and the Younger Dryas. Most sites are situated on dunes, cover sands or edges and slopes of river terraces. This paper focuses on the settlement pattern and the raw material distribution which indicate a highly mobile life-style and significance of human contacts in the Younger Dryas. In the relatively stable environmental conditions of the late Alleröd and in the very beginning of Younger Dryas, when the area was covered by forest, the first Tanged Point Complex communities arrived. The forest landscape was rich in natural resources and suitable for hunting. Later in the Younger Dryas, a climatic change caused the increase of floods, permafrost reactivation and riparian forest extinction. Human groups moved away from the area. The occurrence of exotic raw material confirms migration of hunter groups in the late Younger Dryas in the latitudinal direction. Camp sites were situated on more elevated inland surfaces of terraces and dunes. Most probably at the end of the Younger Dryas, Sviderian hunters migrated from the Koło Basin and followed the herds of animals far north. After the stabilization of environmental conditions, hunters came back to the Koło Basin.

Taphonomy and paleoenvironmental conditions of deposition of fossil whales in the diatomaceous sediments of the Miocene/Pliocene Pisco Formation, southern Peru—A new fossil-lagerstätte

The Pisco Formation in Peru contains abundant fossil cetaceans in middle Miocene to lower Pliocene sandstone, siltstone, and tuffaceous and diatomaceous mudstone. Fossil whales are especially abundant in the uppermost diatomaceous units. Most specimens are well articulated or partially disarticulated but associated. Degree of preservation is exceptionally high and uniform among articulated and disarticulated specimens and on the lower and upper surfaces of the bones. Some specimens have baleen preserved in anatomical position. Bones show no evidence of bioerosion by macro- or micro-invertebrates, except for a very limited amount of microbial borings. Diatomaceous layers seem to lack bioturbation. However, bioturbation did occur in a few tuffaceous silty and sandy layers of the lower part of the formation. Shark teeth are found associated with many of the specimens; however, despite abundance of whale skeletons, shark tooth marks are extremely rare. Several lines of evidence indicate that sediments and whales were deposited in a shallow-to-deep shelf environment (an embayment), and not in a beach environment. The thick diatomaceous successions record conditions of strong ocean upwelling indicated by the abundant occurrence of the diatom species Thalassionema nitzschioides. The exceptional preservation of diatom frustules suggests that they reached the seafloor very rapidly and were not successively reworked. The hundreds of whale specimens found, their excellent preservation, and their high degree of articulation make the Pisco Formation fossil whales the best representative assemblage of fossil Mysticeti known so far. The abundance of whale skeletons and other vertebrates in the diatomaceous beds, their excellent preservation, including evidence that soft tissue (baleen) was still present at burial, and the degree of articulation, point to frequent mortalities followed by rapid sedimentation that prevented decay of the skeletons and colonization by invertebrates. Sedimentation rates appear much higher than rates inferred from some other modern and ancient settings where whale skeletons have been found.

Polygenetic sand volcanoes: On the features of liquefaction processes generated by a single event (2012 Emilia Romagna 5.9 Mw earthquake, Italy)

One of the most important geological effects generated by the seismic events of Emilia Romagna (Italy, 2012) was the liquefaction. The first earthquake took place on 20th May (5.9 Mw) and generated liquefaction in the locality of San Carlo, mainly recorded as large fissure sand volcanoes. Detailed stratigraphic and sedimentology analyses of these sand bodies indicated the assemblage of rhythmic normal graded beds of sand for many individual sand volcanoes. This is interpreted as repeated individual sand extrusions generating polygenetic sand blows for a single earthquake. This original analysis, made for first time in a case of extensive seismic liquefaction, indicates that the different pulses sand extrusion occurred after seismic shaking, and therefore no related to the cyclic seismic shearing stimulated by surface seismic waves. Underground liquefaction of shallow sandy layers and ground cracking, assisted by relevant lateral spreading, promoted water and sand ejections (E–W direction). Localised and repeated ground subsidence and bulging supported by the ejection of the underlying fluidized sediments feedback transient ground undulations and repeated sand ejections. The unstable undulating behaviour of the ground reinforced and sustained the liquefaction process through time after the seismic shaking, leading the occurrence of polygenetic sand volcanoes. In summary, the seismic liquefaction is the starting point of the process, although only if these sand ejections could promote the instability of the ground since underground sand depletions feedback the liquefaction process through time. The process stops when the hydrostatic balance is recovered in the affected zone.

Description of partial sandy layers of dredged clay deposit using penetration resistance in installation of prefabricated vertical drains

The dredged soil dumped into a reclamation facility is generally heterogeneous. If the reclamation is executed using hydraulic transportation through pipes, large particles will be deposited around their outlets, and fine particles will be deposited apart from those outlets, resulting in significant grain size segregation. Therefore, ground improvement by applying a preload or vacuum to the dredged soil deposit with prefabricated vertical drains (PVDs) may result in an unexpected differential settlement. In the present study, partial sandy layers in a dredged soil deposit were identified as three-dimensional information using the penetration resistance of the mandrel in the PVD installation, which was recorded as dense information for a wide region. It was clarified that the depth profile of the penetration resistance of the mandrel in the PVD installation was useful for investigating the soil stratigraphy, because it is closely related to the depth profile of the tip resistance in cone penetration tests (CPTU). The relative penetration resistance, defined as the penetration resistance eliminating the data trend that reflects the effects of the overburden stress, shear strength, sleeve friction and buoyance, is useful for identifying the partial sandy layers in a dredged soil deposit. A classification equation was proposed for identifying the partial sandy layers. Firstly, the depth profile without the sandy layer was approximated, and then the threshold value of 1.0MN/m2 was used to identify the partial sandy layer. To verify the availability of this proposed method, the depth profiles were compared with the results of CPTU tests. In addition, the predicted settlement, calculated on the basis of the stratigraphy obtained using the penetration resistance of the PVDs, was compared with the ground surface profile leveled after vacuum consolidation.

Dynamical effects during compaction band formation affecting their spatial periodicity

AbstractCompaction bands (CBs) are responsible for significant anisotropy alterations of permeability in geological materials; hence, understanding their formation conditions appears of key importance to all applications involving fluid extraction/injection from/into the ground. While most of the available models to understand CB formation are focused on interpreting the onset of a single CB, little effort has been so far dedicated to understand the documented periodicity of CBs. In this paper, the role of dynamical effects in inducing the post onset evolution of CBs is analyzed by means of a dedicated model for porous media with compressible constituents, with reference to a horizontal layer of sandy, water‐saturated material. Elastic waves are generated as a first CB occurs due to sudden, localized volumetric collapse. If the waves are reflected at the interface with a softer material or with a previously formed CB, they produce significant local effective stress concentrations, which can promote the formation of further CBs in a cascade fashion, according to a regular geometric pattern. The spatial distribution of dynamically generated CBs, as well as the extent of the phenomenon, depends on the geometry of the domain and on the material's permeability. Sensitivity analysis is also performed to assess the key properties that promote dynamical CB in situ formation, identifying as the most influential conditions large stratum stiffness (increasing with depth) and the presence of softer layers. In contrast, the presence of less permeable and/or stiffer layers is not believed to play a major role in the proposed mechanism.

An Aseismic Design Method For Preventing Damage Of A Soil-pile Foundation-super Structure System

An effective aseismic design method for the conditions of ground improvement is proposed for preventing liquefaction of ground and reducing damage of pile foundations. The proposed method uses two existing computer programs; NUW2 for 2D effective stress analysis and WAP3 for simulation of the sand compaction pile method. The analysis is extended to take the soil-pile interaction into consideration. Numerical computations for responses of the ground and the pile foundations are performed for the 22 ground models in the Kobe area. By using the natural period of the ground as the key parameter, the critical conditions of ground improvement are evaluated and related with the responses of pile and superstructure on the ground. The main conclusion is that the proposed method is effective for reducing pile stress under an allowable limit by ground improvement in sandy layers, but the ground improvement is difficult to prevent pile failure in soft clayey ones.

Iceberg ploughmarks illuminated by shallow gas in the central North Sea

Conventional 3D seismic data provides direct evidence for glacial influence during the early Pleistocene sedimentation in the Central North Sea. We identify iceberg ploughmarks as dim linear to curve-linear features in three early Pleistocene horizons that have high reflection amplitude compared to adjacent horizons. The anomalous horizons are interpreted to be reflections from thin sandy layers saturated with gas. The gas acts as a contrast liquid illuminating the thin sand layers. The reason for this is the difference in acoustic properties between water and gas saturated sand layers. The combination of thin bed effects and shallow gas makes the iceberg ploughmarks easily detectable as dim features in seismic reflection amplitude maps. Our interpretation is based on analysis of real seismic data, well logs and modeled seismic response. The methods we use include interpretation of horizons followed by extraction of reflection amplitudes, well log analysis, pre-stack amplitude versus offset analysis of high resolution 2D seismic data and time-lapse analysis of seismic. Seismic modeling is performed to study interactions between thin sand beds, shallow gas and iceberg ploughmarks. A new trapping mechanism for shallow gas is presented and seismic modeling of this trap strengthens our interpretation. The trap is created by iceberg ploughmarks in sandy layers that are covered by finer and less permeable sediments. For this area we find that conventional seismic interpretation is superior to the much used method of studying seismic time-slices for detection of iceberg ploughmarks, both with respect to time and detectability. This study shows that the interpreter should look for high amplitude horizons with amplitude variations laterally when trying to detect iceberg ploughmarks.

The Shaking Frequency Effect in the Dynamics of a Model Sandy Layer

Experimental results showing the frequency-dependent behavior of both dry and saturated sandy layers subjected to a horizontal excitation on a shaking table are presented. The largest settlements of a dry layer correspond to two specific frequencies. In the case of a saturated layer, there is a single peak frequency corresponding to the largest depth of sinking of a measuring plate in liquefied subsoil. The first peak of settlements coincides with the single peak of sinking in liquefied soil. The eigenfrequencies of the layer were estimated. A modification of the compaction law was proposed for low shaking frequencies.

Paleosols and paleoenvironments of early Mars

Fluviolacustrine sediments filling Gale Crater on Mars show two levels of former exposure and weathering that provide new insights into late Noachian (3.7 ± 0.3 Ga) paleoenvironments of Mars. Diagnostic features of the two successive paleosols in the Sheepbed member include complex cracking patterns of surface dilation (peds and cutans), a clayey surface (A horizon), deep sand-filled cracks with vertical lamination (sand wedges), and replacive sulfate nodules aggregated into distinct bands (gypsic By horizon) above bedded sandy layers (sedimentary C horizon). Shallow gypsic horizon, periglacial sand wedges, and limited chemical weathering are evidence of a hyperarid frigid paleoclimate, and this alternated with wetter conditions for the lacustrine parent materials in Gale Crater during the late Noachian. Depletion of phos- phorus, vesicular structure, and replacive gypsic horizons of these Martian paleosols are fea- tures of habitable microbial earth soils on Earth, and encourage further search for definitive evidence of early life on Mars.

Cotton Growth, Yield, and Fiber Quality Response to Irrigation and Water Deficit in Soil of Varying Depth to a Sand Layer

Research was conducted in 2010 and 2011 at the West Tennessee Research and Education Center in Jackson, TN to investigate irrigation response in cotton. The objective of this study was to evaluate plant response to four different irrigation regimes by using main-stem node counts, quantification of canopy light interception, and canopy temperature, while making comparisons across two soils that vary in depth to a sandy layer. PHY 375 WRF cottonseed was planted in a no-tillage system in 9-m rows on 97-cm spacing with 10.5-12 seed m-1 of row. Irrigation was applied from drip tape lying in the row furrow at rates of 0, 1.27, 2.54, and 3.81 cm week-1. Comparisons were made across deep soils (no sand layer within the top 89 centimeters of soil) and shallow soils (sand layer within the top 61 centimeters of soil). Plant height, number of nodes, nodes above white flower (NAWF), canopy light interception, and canopy temperature were monitored during the blooming period of the crop each year to determine differences in irrigation response. Cotton plants grown in deep soils had higher vegetative biomass, total number of nodes, plant height, light interception, fiber quality, yield, and reduced canopy temperature compared to plants grown in the shallow soil. Similarly, irrigation increased cotton plant vegetative biomass, total number of nodes, plant height, light interception, fiber quality, yield, and reduced canopy temperature compared to dryland cotton. Results from this trial indicate that differences in physiological growth patterns, canopy density, canopy temperature, lint yield, and fiber quality are evident when compared across irrigation amounts and soil depths.

Usage of chitosan on the complexation of heavy metal contents and vertical distribution of Hg(II) and Cr(VI) in different textural artificially contaminated soils

Chitosan has been adopted to remedy artificially contaminated soils with heavy metals of Hg(II) and Cr(VI) in this study. With application of chitosan of different concentrations, results demonstrated that within the first 7 days, available Hg(II) and Cr(VI) contents in three textural artificially contaminated soils of clay, loam and sandy decreased significantly. The contents of heavy metals in these three artificially contaminated soils decreased later than 7 days with the chitosan application. Moreover, the available Hg(II) and Cr(VI) contents in artificially contaminated soil layers of 5 cm significantly reduced than that in 15 and 25 cm after 7 days of chitosan with 1.15 g kg−1 DW (dry weight). The available Hg(II) and Cr(VI) contents in loam layers of 5 cm significantly decreased than that in 15 and 25 cm after 7 days of chitosan with 1.15 g kg−1 DW. The available Hg(II) and Cr(VI) contents in sandy layers of 5 cm significantly reduced than that in 15 and 25 cm after 7 days of chitosan with 1.15 g kg−1 DW. It also decreased after 7 days of chitosan’s application. Results suggested that application of chitosan with 1.15 g kg−1 DW soils of 7 days could improve the remediation of the soil contaminated by Hg(II) and Cr(VI) in the industrial application.