Tension of Geosynthetic Material Regarding Soils on Landfill Liner Slopes

Proc. Natl. Sci. Counc. ROC(A)Vol. 25, No. 4, 2001. pp. 211-218

C HIA

-N AN LIU

Civil Engineering Department National Chi-Nan University

Puli, Nantou, Taiwan, R.O.C.

(Received July 17, 2000; Accepted October 31, 2000)

introduced. The existing conventional analytical methods consider the force equilibrium but ignore displacement compatibility. They usually can not obtain a reasonable estimation. A new analytical method that satisfies both the force equilibrium and displacement compatibility is presented in this paper. The conventional and proposed methods were used to evaluate the tension of geosynthetic materials within a tested landfill. Compared with field measured values, the estimation of the induced tension obtained using the proposed method is more accurate than that obtained using the conventional method. Application of proposed method reveals that the tensions within geosynthetic components increase as placement of soil continues. The proposed method is a useful tool for evaluating the system stabilities of landfill liner systems.

Key Words: landfill, liner, slope, geosynthetic, tension

I. Introduction

For a modern municipal solid waste landfill or a haz-ardous waste landfill, a liner system is a mandated component.The schematic of a typical landfill liner system is shown in Fig. 1. In general, a liner system is composed of barrier,drainage, and cover layers which fulfill the purpose of sepa-rating buried waste or leachate from the underlying soil and groundwater. A conventional landfill liner requires a layer of cover soil to protect the underlying drainage layer and barrier layer from sunlight, stone penetration and other adverse factors.Recently, the application of geosynthetic materials in geotechni-cal facilities has become widespread. For example, geomem-branes have been applied as barrier layers and geotextiles as drainage layers. The application of geosynthetic materials has become common because they have some financial and en-gineering advantages over soil materials. For example, com-posite lining systems containing geosynthetic and soil mate-rials are used extensively in waste containment facilities, as shown in Fig. 1. Estimating the tension in geosynthetic materials is important for determining the stability of a landfill liner system because the geosynthetic materials could rupture due to the existence of tensile stresses. In addition, the expected loads carried by geosynthetic components need to be deter-mined in order to design geosynthetic anchorage systems (Koerner, 1997). The long-term performance of geosynthetic

materials in terms of leachate resistance and creep resistance is also a function of tensile stress (Haxo and Waller, 1987).Therefore, it is important to evaluate the tension in geosynthetics induced by downward dragging of cover soils on geosynthetic materials.

The conventional methods for evaluating the tension within geosynthetic materials in a contamination system are basically based on the limit state equilibrium assumption. For example, Giroud and Beech (1989) assumed that the com-ponents, including both the soil and geosynthetic materials,above the potential failure surface act as a sliding body along the potential failure surface. Tension is induced in geosynthetic materials when the buttress resistance (i.e., the resistance of the slope toe) and interfacial shear resistance are fully developed.

Fig. 1. Schematic of a landfill liner system.

C.N. Liu However, the deformations required to develop the same level

of safety for the interfacial shearing mechanism, buttress compression mechanism and geosynthetics extension mecha-

nism may not be similar. The shear displacement for the peak shear strength of a geosynthetic interface is usually less than

1 centimeter (Gilbert et al., 1995), while the axial strains for

full development of axial resistance are on the order of several percents for soils and geosynthetic materials. That is, an axial deformation of from centimeters to meters is required for soil

and geosynthetic materials to develop peak axial strength. In

the approach proposed by Koerner and Hwu (1991), the tension within each geosynthetic layer is calculated as the difference

between the shear stress on the overlying interface and the fully mobilized shear resistance on the underneath interface. This assumption may not be reasonable unless all the interfaces are on the verge of sliding simultaneously. These conventional methods are not adequate because only the force equilibrium is satisfied, while the displacement compatibility between the soil buttress, geosynthetic materials and failure surface is not considered at all.

In this paper, a new analytical method that considers displacement compatibility in estimating the tension in geosyn-thetic materials in a landfill liner system is introduced. The assumptions and approaches employed in this method are presented. Validation of this method is demonstrated. This proposed method is applied to example problems to show how the placement of soils affects the tension in geosynthetic ma-terials. The proposed method is also applied to a lining system composed of multiple geosynthetic layers to highlight the importance of considering different failure mechanisms. II. Proposed Approach

The soil materials, which are placed on landfill liner slopes, tend to slide down because of the weight. For a construction lift with a height of h (Fig. 1), the shear force (F) applied to the lining system due to the weight (W) of soil lift is

F = W sinβ,(1) where β is the slope angle. It is easy to include the weight of construction equipment if appropriate. Slippage will occur within the lining system at the interface with the smallest interface shear strength. Since the relative displacement for the development of the shear strength of a geosynthetic-soil interface is very small compared with the deformation nec-essary for the development of the axial strength of soil and geosynthetic materials, the large displacement strength along this interface will be mobilized earlier than the ultimate soil buttress resistance and the ultimate geosynthetic tension. The shear strength provided by the potential failure surface is S LD = c LD L h + N tanφLD,(2)where S LD is the shear force mobilized at the interface cor-responding to large shear displacement, c LD and φLD are the strength parameters of the Mohr-Columb envelope corre-sponding to large shear displacement for the appropriate normal stresses range, L h is the slope length along the lift (L h = h/sinβ), and N is the normal component of the applied force acting on the interface. It is assumed that the force at the toe of the soil layer (i.e., the soil buttress force C soil) is oriented parallel to the slope; therefore, the normal component, N, is estimated as

N = W cosβ.(3)

Since the thickness of the soil is usually uniform along the liner slope, the shear force due to the weight of the soil layer is applied as uniformly distributed shear stresses, f, where

f = F/L h.(4)

Similarly, the mobilized shear resistance, s LD, is assumed to be uniformly distributed over the interface, that is, s LD = S LD/L h.(5) The net uniformly distributed shear stresses, f net, are equal to the difference between the shear stresses and the mobilized shear resistance, i.e.,

f net = f?s LD.(6)

The net shear stresses need to be balanced by the induced compression (C soil) within the soil buttress and tensions (T gs) within the geosynthetic materials. The force equilibrium dia-gram of the lift of a liner slope is shown in Fig. 2.

In this approach, the soil and geosynthetic components above the slippage plane are treated as a simple, composite column with fixed ends. One fixed end of this composed co-lumn is at the anchor trench, and the other is at the slope toe of the cover layer. The proposed approach is called the “simple composite column method,” and the composite column is illustrated in Fig. 3. The geosynthetic and soil components

are assumed to behave as elastic-plastic materials. Therefore, Fig. 2. Force equilibrium diagram of a lift of a liner system.

Tension of Geosynthetic Material

appropriate “elastic” stiffness should be selected with the expected levels of deformation considered. The soil exhibits an axial stiffness in compression (K c ) but no stiffness in tension (K t ), while the geosynthetic layer exhibits tensile stiffness but no stiffness in compression. No slippage is assumed at the interface between the two structural layers; therefore, the two columns must strain equally. For multiple components (e.g.,several layers of geosynthetics in tension), the equivalent stiffness (K ) is

K =

K i Σi =1

n ,(7)

where K i is the stiffness of the i th geosynthetic component.

When construction of the cover layer is conducted, the soil is pushed on the slope in lifts. For each lift of soil, the interfacial shear resistance balances the shear stresses induced by the soil weight. For the shear stresses that are not balanced,compression within the compressible column (soil layer) and tension within the tensile column (geosynthetic materials) are induced. Compressible and tensile strain is correspondingly induced within the composite column. Since shear stress is applied over lift length, it is assumed that the tensile strain is constant over the length of the exposed geosynthetics above the lift, and that the compressible strain is also constant over the length of the pre-placed soil below the lift. The distribution of strain in the composite column induced by one lift of soil is shown in Fig. 4. The lengths of the lift under tension and compression are represented by L t and L c , respectively. The tensile load in the geosynthetics, T gs , and the compressive load in the soil, C soil , are given by

T gs = f net L t ,C soil = f net L c .

(8)

These lengths are obtained by setting the displacement in the tensile component equal to that in the compressive component at the point of zero strain (Fig. 4), that is,

T K t (L –L h )+T 2K t L t =C 2K c

L c .(9)

Relating T gs and C soil in terms of f net , L t can be solved using the quadratic equation

(1–

K t K c )L t 2+2[(L –L h )+K t K c L h ]L t –K

t K c L h

2=0, (10)and L c can be calculated using the following equation:

L c = L h ? L t .

(11)

Once L c and L t are obtained, the compressive load in the soil (

C soil ) and the tension in the geosynthetic materials (

T gs ) can be found using Eqs. (6) and (8). The distribution of tensile load among multiple components can be determined by as-suming equal strain in all tensile components above the plane of slippage. For each component, the induced tension can be calculated as the product of the total tensile load and the proportion of its stiffness to that of the total tensile stiffness.

As the next lift of soil is placed on the slope (Fig. 1),the net shear stress caused by this lift will induce more tension in the geosynthetic materials. The tension induced by this new lift can be calculated using Eqs. (1) ? (11). The tensile strains in the geosynthetic components accumulate as the next lift of soil is placed on the slope.

III. Validations

The proposed approach will be validated through a com-parison between analytical results and experimental results obtained in a full-scale experiment described by Villard et al .(1997). The full-scale experiment was carried out in France.A liner system comprised of compacted clay (base layer), a 2-mm thick HDPE geomembrane (GM), a BIDIM666 non-woven geotextile (GT), and a 30-cm thick granular material was selected as the instrumented test cell. The height of this liner slope was 4 meters, and the inclination (β) was 26.6°(2H:1V). The tensile stiffness values of the geotextile and

Fig. 3. Illustration of a simple composite column method.

Fig. 4. Distribution of strain along the length of the slope.

C.N. Liu geomembrane were 65 and 458 kN/m, respectively. These values were determined in the laboratory. The granular material

was assumed to have a Young’s modulus of 1200 kPa and

a volumetric weight of 18 kN/m3. The friction characteristic

of the potential sliding surface (GM/clay) measured in the laboratory had a friction angle (φLD) of 9°. During the test,

the granular soil layer was loaded meter by meter on the slope

until a loading length of 6 m was obtained. The tensile forces

at the anchored top of the geotextile and geomembrane were measured during the test. More details about this experiment were presented in Villard et al. (1997).

The proposed analytical approach was applied in this

field-scale experiment to estimate the induced tension within

the geosynthetic materials. To demonstrate application of the proposed method, step-by-step calculations are presented below.

(1)The shear force (F) induced by one lift of granular

soil is 2.41 kN/m. ? Eq. (1)

(2)The normal force (N) provided by one lift of granular

soil is 4.83 kN/m. ? Eq. (3)

(3)The shear stress (f) induced by one lift of granular

soil is 2.41 kPa (L h = 1 m). ? Eq. (4)

(4)The shear resistance (s LD) mobilized on sliding sur-

face is 0.76 kPa. ? Eq. (2) and Eq. (5)

(5)The net uniformly (f net) distributed shear stresses is

1.65 kPa. ? Eq. (6)

(6)The equivalent stiffness (K = K gt + K gm) of the

geosynthetic materials is 523 kN/m. ? Eq. (7) (7)When the first lift of granular material is placed on

slope, the exposed length of the geosynthetic material is 7.94 m, and the pre-placed length of the soil is zero.

Putting these values into Eqs. (10) and (11), the lengths of the lift in tension (L t) are calculated as

0.077 m.

(8)The induced geosynthetic tension (T gs) induced by

placement of first lift of granular material is 0.128 kN/m. ? Eq (8)

(9)The induced tension at the top of the individual

geosynthetic components is calculated as

T gt = T gs K gt/(K gt + K gm) = 0.016 kN/m,

T gm = T gs K gm/(K gt + K gm) = 0.112 kN/m.

(10)As the process of soil placement continues, the above

procedures (1) through (6) can be skipped if the shear

stress and shear strength are uniform along the slope.

The induced geosynthetic tension is calculated by

repeating procedures (7) to (9). For example, when

the second lift of soil is placed, the exposed length

of the geosynthetic materials is 6.94 m, and the pre-

placed length of the soil is 1 m. The geosynthetic

tension (T gs) induced by placement of the second lift

of granular soil is 0.319 kN/m. Therefore, the ac-

cumulated tension at the anchored top after two lifts

of soil are placed is 0.447 kN/m.

The calculations can be easily performed using a spreadsheet, as shown in Table 1. A comparison of the analyti-cal results obtained using the proposed approach with the measured results (Villard et al., 1997) is shown in Fig. 5. The results obtained using Koerner and Hwu’s approach (Koerner and Hwu, 1991) are also shown in this figure for reference. The figure reveals that the proposed approach gives more accurate results in estimating the geosynthetic tensions in the landfill liner slopes.

IV. Tension of Geosynthetic Materials The field measurements of a test landfill liner slope were employed to validate the proposed analytical approach. The

proposed approach was used to analyze typical landfill liner Fig. 5. Comparison of geosynthetic tensions.

Table 1. Spreadsheet for Calculating Geosynthetic Tensions

Exposed Pre-placed Tension for Lift Accumulated Tension Lift Geosynthetic Soil L t T total GT GM Length (m)Length (m)(m)(kN/m)(kN/m)(kN/m)(kN/m) 17.940.00?0.4518.8 ?1.50.080.130.130.020.11

2 6.94 1.00?0.4522.6 ?4.40.190.320.450.060.39

3 5.9

4 2.00?0.4526.4 ?7.30.280.460.900.110.79

4 4.94 3.00?0.4530.2?10.20.340.56 1.460.18 1.28

5 3.94 4.00?0.4534.0?13.10.390.64 2.100.2

6 1.84

Parameters for Quadratic Equation

Tension of Geosynthetic Material

slopes together more information. The geometry and con-figuration of the example landfill liner slope are shown on Fig. 6. The maximum axial load and stiffness for the various components of this example are shown in Table 2. These data,adopted from Koerner (1997), are typical results of tensile tests in wide width specimens. The shear resistance parameters,presented in Table 3, for the various combinations of interfaces are also typical values collected from published reports (Carroll and Chouery, 1991; Criley and John, 1997; Koutsourais et al .,1991; Liu et al ., 1997; Martin et al ., 1984; Williams and Hou-lihan, 1987). For this example of a landfill liner slope, the potential sliding surface was the interface between the geonet and geomembrane. Therefore, the cover soil was compressed and the geotextile and geonet extended to resist downslope movement. The geosynthetic tensions were calculated using the proposed approach. Figure 7 shows the relationship be-tween the tension and the process of cover soil placement.The induced tension increased as the length of the soil place-ment increased. This relationship is not linear. Geosynthetic components attract more tensile load, so the curves on Fig.7 are concave. Therefore, the most critical situation occurs

when placement of the cover soil layer is finished. The effect of the lift length on the accumulated tension is shown in Fig.8, which reveals that the lift length of the soil placement does not have a significant impact on the induced tension when it is smaller than 20 m (about one quarter of the slope length).However, significant tension is induced if the lift length is large. For example, the tension induced by the placement of a lift length of 80 m is about 50% more than the tension induced by a lift length of 20 m. This analysis is important for deciding the optimum construction process. To minimize the geosynthetic tension, based on the limit information obtained from this example, it is recommended that the length per soil lift be smaller than one quarter the slope length.

Koerner (1997) proposed a method to calculate the factor of safety of geosynthetic tension failure in landfill liner slopes.In this method, the sliding object is identified as an active wedge and a passive wedge. The main resistant mechanism in a passive wedge is the soil passive force, while in an active wedge, the main mechanisms are geosynthetic tension and shear strength. The factors of safety for these resistance me-chanisms are assumed to be the same based on the limit

equilibrium assumption. The assumptions and procedures of

Fig. 6.

Schematic of an example landfill liner system (not to scale).

Fig. 8.Induced geosynthetic tension in the example landfill liner slope for

different lift lengths.

Fig. 7.Geosynthetic tension in the example landfill liner slope (lift length

= 5 m).

Table 2. Axial Properties of Example Landfill Liner Components

Stiffness, EA Peak load, P Liner Component (kN/m)(kN/m)Cover soil ?600?180Geotextile 7227Geonet

4512Geomembrane

300

20

Note: Negative values represent compressive properties.

Table 3. Typical Shear Strength Parameters of Geosynthetic Interfaces Geosynthetic Shear Strength Parameters Interface

c (kPa)φ (°)geomembrane/geonet 0 8geotextile/geonet 015geotextile/san

d 030geomembrane/clay

010textured geomembrane/geotextile

20

C.N. Liu

this method were described in Koerner (1997). This method was applied to the landfill slope example. The factor of safety was found to be 0.78. (The cover soil was assumed to be a frictional material with a friction angle of 30°.) This means that the geosynthetic material was overstressed, and that tension failure was induced.

In general, several options can be selected to increase the stability of a landfill liner slope. The slope configuration is usually selected to increase the stability of a landfill liner slope. For example, for the liner slope depicted in Fig. 6 (con-figuration A), the composition of the drainage layer is changed from a geotextile/geonet composite to a geotextile/geonet/ geotextile composite. The underlying geomembrane is changed so that it is textured on its upper surface and smooth on its lower surface. For the new configuration (configuration B), the interface with the minimum shear resistance is now located at the smooth geomembrane/clay interface (Table 3). These changes are typically adopted because the friction angle of the potential sliding surface is increased from 8° to 10°, and more geosynthetic tensions are provided by geomembrane and geotextile layers. Using Koerner’s method (Koerner, 1997) to achieve stability of the new configuration justifies the change. The factor of safety increases from 0.78 to 1.14 (Table 4). However, according to the analysis results obtained using the proposed approach, the change of configuration does not help the stability significantly. The ratios of the maximum induced tension to the peak tension of all the geosynthetic materials are presented in Table 4. The lift length in the analysis is 20 m. It is noted that though the maximum tensile loads in the geotextile and geonet decrease significantly when the liner configuration is changed, considerable tension in the geomembrane is induced. The ratio of the induced tension to the peak tension of the geomembrane in configuration B is even larger than that of the geonet in configuration A. Although there is less applied shear stress due to the increased interface strength at the slip plane, the geosynthetics attract greater loads because the stiff geomembrane is now above the slip plane. This analysis provides information useful for designing geosynthetic liner slopes. For a multi-layered system composed of different failure mechanisms, assessment of all the possible mechanisms is important and necessary. V. Conclusions

A new approach to estimating the tension within geo-synthetic materials in soils on landfill liner slopes has been proposed in this paper. The shear strength along the failure surface is assumed to develope fully before mobilization of the soil buttress and geosynthetic tensions begin. The material above the failure surface is assumed to be a composed of a compressive column and a tensile column. The levels of mo-bilized compression and tension are calculated so as to satisfy the displacement equilibrium between the compressive col-umn and tensile column. This approach is simple but accurate. Comparison with results obtained in field tests has validated this approach. A lot of information about geosynthetic tension can be obtained in the analysis by using this approach. The induced tensions increase as the waste filling process con-tinues. When the length of soil per lift is less than one quarter of the slope length, the lift length does not significantly in-fluence the magnitude of the tension. Because a typical landfill liner system is composed of multiple failure mechanisms, evaluation of all the failure mechanisms is important to assess the stability of the whole system. Compared with the con-ventional analysis methods, the proposed method is more capable of calculating the factor of safety of geosynthetic tension failures.

Nomenclature

C soil soil buttress force

F applied shear force

H slope height

K stiffness

K c stiffness of compressive components

K t stiffness of tensile components

L c lengths of the lift in compression

L h slope length along the lift

L t lengths of the lift in tension

N applied normal force

S interface resistance

S LD shear force mobilized at the interface corresponding to large shear displacement

T gs tensile load

W weight of soil

c LD parameter of the Mohr-Coulomb envelope corresponding to large

shear displacement

f uniformly distributed shear stresses

f net net uniformly distributed shear stresses

h lift height

s LD mobilized interface shear stresses corresponding to large shear displacement

βslope angle

φLD parameter of the Mohr-Coulomb envelope corresponding to large shear displacement

References

Carroll, R. G., Jr. and C. V. Chouery (1991) Geogrid reinforcement in landfill closures. Geotextiles and Geomembranes, 10, 471-486.

Criley, K. R. and D. S. John (1997) Variability analysis of soil v.s. geosynthetic interface friction characteristics by multiple direct shear testing.

Geosynthetics ’97 Conference Proceedings, 2, 885-897.

Gilbert, R. B., C. N. Liu, S. G. Wright, and S. J. Trautwein (1995) A double shear test method for measuring interface strength. Geosynthetics ’95

Table 4. Analysis Results for Different Configurations

Maximum Induced

Factor of Safety

Configuration Tension/Peak Tension (%) (in Koerner’s method)

GT GN GM A0.7840570 B 1.14111560

Tension of Geosynthetic Material

Conference Proceedings, 3, 1017-1029.

Giroud, J. P. and J. F. Beech (1989) Stability of soil layers on geosynthetic lining systems. Geosynthetics ’89 Conference Proceedings, 1, 35-46. Haxo, H. E., Jr. and M. J. Waller (1987) Laboratory testing of geosynthetics and plastic pipe for double-liner systems. Geosynthetics ’87 Conference Proceedings, 1, 35-46.

Koerner, R. M. (1997) Designing with Geosynthetics, 4th Ed. Prentice Hall, Englewood Cliffs, NJ, U.S.A.

Koerner, R. M. and B. L. Hwu (1991) Stability and tension considerations regarding cover soils on geomembrane liner slopes. Geotextiles and Geomembranes, 10, 335-355.

Koutsourais, M. M., C. J. Sparague, and R. C. Pucetas (1991) Interfacial friction study of cap and liner components. Geotextiles and Geomem-branes, 10, 540-548.Liu, C. N., R. B. Gilbert, R. S. Thiel, and S. G. Wright (1997) What is an appropriate factor of safety for landfill cover slopes. Geosynthetics ’97 Conference Proceedings, 1, 481-496.

Martin, J. P., R. M. Koerner, and J. E. Whitty (1984) Experimental friction evaluation of slippage between geomembranes, geotextiles and soils.

Proceedings of the International Conference on Geomembranes, pp.

191-196, Denver, CO, U.S.A.

Villard, P., J. P. Gourc, and N. Feki (1997) Anchorage strength and slope stability of a landfill liner. Geosynthetics ’97 Conference Proceedings, 1, 453-466.

Williams, N. D. and M. R. Houlihan (1987) Evaluation of interface friction properties between geosynthetics and soils. Geosynthetics ’87 Confer-ence Proceedings, 2, 616-627.

C.N. Liu

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保留建筑EXISTING BUILDING 已建建筑AS-BUILT 新建建筑NEW BUILDING 道路ROADWAY 绿化LANDSCAPE 汽车流线CAR ACCESS 行人流线WALK ACCESS 消防车流线FIRE BRIGADE ACCESS 货车流线TRUCK ACCESS 自行车流线BICYCLE ACCESS 消防车道FIRE WAY 主出入口MAIN ENTRENCE 保安室NO.1 GUARD HOUSE 主出入口 1 EXIT 1 地下车库出口BASEMENT PARKING EXIT 自行车停车场BICYCLE PARKING 自行车停车位BICYCLE STAND 总停车位CAR PARK 其中INCLUDE 地上停车位AT-GRADE CAR PARK 地下停车位UNDERGROUND CAR PARK 空调管线AIR CONDITIONING 强电电缆LV 10KV 弱电电缆ELV 电缆10KV HV 供水管SUPPLY WATER 污水管WASTE WATER 雨水管RAIN WA TER 消防管线FIRE HYDRANT 西门子(中国)总部SIEMENS CENTER BEIJING 说明NOTE 1.本图依据城市道路高程及市政管线标高等 资料并结合场地排水、场地地形、土方平衡 等因素进行竖向设计。 1.THE DRAWING WITH "VERTICAL HEIGHT DESIGN" IS BASED ON CITY ROADWAY ENGINEERING WITH CITY BUREAU PIPELINE HEIGHT INDICATION DOCUMENT SITE DRAINAGE, SITE TOPOGRAPHY, AND SOIL BALANCE ARE INCORPORA TED INTO THE DESIGN. 2.本图所用坐标系统为北京市城市坐标系统， 所用高程为规划高程。 2.THE DRAWING INCORPORATES BEIJING CITY COORDINA TE SYSTEM. ALL THE INDICATIVE HEIGHTS ARE PLANNING HEIGHTS. 3.图中道路横坡按1.5%设计，最小纵坡为 0.2%。 3.ALL THE ROADWAY INDICATED ON THE DRAWING IS BASED ON 1.5%HORIZONTAL SLOPE.THE SMALLEST VERTICAL SLOPE IS 0.2%. 4.图中标注单位均为米。 4.BASIC UNIT OF MEASUREMENT IS METRIC. 保留建筑EXISTING BUILDING 已建建筑AS-BUILT 新建建筑NEW BUILDING 道路ROADWAY 绿化LANDSCAPE 地下车库入口BASEMENT PARKING ENTRANCE 坡道RAMP 消防车道FIRE WAY 紧急出口EMERGENCY EXIT 3 2#保安室NO.2 GUARD HOUSE 停车场PARKING 工程地点位置图SITE LOCATION 图例LEGEND 自行车停车场BASEMENT EXIT 1 BICYCLE PARKING H=4.8M 地下室出入口 2 BASEMENT EXIT 2 主出入口 4 PARKING EXIT 4 主出入口 1 EXIT 1 道路ROADWAY 实土绿化COMPACTED SOIL LANDSCAPE 敷土绿化DEPOSITED SOIL LANDSCAPE 通风井VENTILATION OUTLET 冷却塔(两组) COOLING TOWER(2 UNITS) 紧急通道EMERGENCY ACCESS 绿地LANDSCAPE 围挡BARRIER 停车场PARKING 地下车库出入口PARKING ENTRENCE 主出入口MAIN ENTRENCE 1#保安室NO.1 GUARD HOUSE 说明NOTE 1.图中所标注建筑尺寸为外墙皮尺寸. 1.DIMENSIONS INDICA TED ON THE PLAN ARE MEASURED TO EXTERNAL EDGE OF THE BUILDINGS. 2.建筑的坐标点为轴线交点坐标. 2.ARCHITECTURE COORDINATES = INTERSECTION OF THE BUILDINGS AXIS. 3.本图以米为单位,%%P0.000相当于绝对标 高37.75. 3.METRIC SYSTEMS ARE THE UNIT OF MEASUREMENT. 4.本项目对周边现状及规划建筑日照影响满 足相关法规及规范要求, 即日照时数满足大寒日最低2小时的日照要 求. 4.DESIGN COMPLIES WITH LOCAL REGULATION OF SUN SHADING TO NEIGHBORHOOD. 保留建筑面积EXISTING BUILDING 容 积率PLOT RATIO 建筑占地面积BUILDING COVERAGE 建筑密度BUILDING DENSITY 绿化面积GREEN AREA 绿地率GREEN RATIO 总人数TOTAL USERS 机动车停车位CAR PARK 地上其辆65 65 LOTS ABOVE GROUND 地下辆564 中INCLUDE UNDERGROUND 564 LOTS 200辆自行车停车位BICYCLE STAND 200 LOTS 地上辆200 200 LOTS ABOVE GROUND 服务中心SERVICE CENTRE 1号办公楼OFFICE 1 地上 2号办公楼ABOVE GROUND OFFICE 2 地下室出入口1 BASEMENT EXIT1

图像处理中值滤波器中英文对照外文翻译文献

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BN 氮化硼 BNE 新型环氧树脂 BNS β－萘磺酸甲醛低缩合物 BOA 己二酸辛苄酯 BOP 邻苯二甲酰丁辛酯 BOPP 双轴向聚丙烯 BP 苯甲醇 BPA 双酚A BPBG 邻苯二甲酸丁(乙醇酸乙酯)酯 BPF 双酚F BPMC 2-仲丁基苯基-N-甲基氨基酸酯 BPO 过氧化苯甲酰 BPP 过氧化特戊酸特丁酯 BPPD 过氧化二碳酸二苯氧化酯 BPS 4，4’-硫代双(6-特丁基-3-甲基苯酚) BPTP 聚对苯二甲酸丁二醇酯 BR 丁二烯橡胶 BRN 青红光硫化黑 BROC 二溴(代)甲酚环氧丙基醚 BS 丁二烯-苯乙烯共聚物 BS-1S 新型密封胶 BSH 苯磺酰肼 BSU N，N’-双(三甲基硅烷)脲 BT 聚丁烯-1热塑性塑料 BTA 苯并三唑 BTX 苯-甲苯-二甲苯混合物 BX 渗透剂 BXA 己二酸二丁基二甘酯 BZ 二正丁基二硫代氨基甲酸锌 C 英文缩写全称 CA 醋酸纤维素 CAB 醋酸-丁酸纤维素 CAN 醋酸-硝酸纤维素 CAP 醋酸-丙酸纤维素 CBA 化学发泡剂

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Materials Studio是Accelrys专为材料科学领域开发的可运行于PC机上的新一代材料计算软件，可帮助研究人员解决当今化学及材料工业中的许多重要问题。Materials Studio软件采用Client/Server结构，客户端可以是Windows 98、2000或NT系统，计算服务器可以是本机的Windows 2000或NT，也可以是网络上的Windows 2000、Windows NT、Linux 或UNIX系统。使得任何的材料研究人员可以轻易获得与世界一流研究机构相一致的材料模拟能力。Materials Studio是ACCELRYS 公司专门为材料科学领域研究者所涉及的一款可运行在PC上的模拟软件。他可以帮助你解决当今化学、材料工业中的一系列重要问题。支持Windows98、NT、Unix以及Linux等多种操作平台的Materials Studio使化学及材料科学的研究者们能更方便的建立三维分子模型，深入的分析有机、无机晶体、无定形材料以及聚合物。 任何一个研究者，无论他是否是计算机方面的专家，都能充分享用该软件所使用的高新技术，他所生成的高质量的图片能使你的讲演和报告更引人入胜。同时他还能处理各种不同来源的图形、文本以及数据表格。 多种先进算法的综合运用使Material Studio成为一个强有力的模拟工具。无论是性质预测、聚合物建模还是X射线衍射模拟，我们都可以通过一些简单易学的操作来得到切实可靠的数据。灵活方便的Client-Server结构还是的计算机可以在网络中任何一台装有NT、Linux或Unix操作系统的计算机上进行，从而最大限度的运用了网络资源。 ACCELRYS的软件使任何的研究者都能达到和世界一流工业研究部门相一致的材料模拟的能力。模拟的内容囊括了催化剂、聚合物、固体化学、结晶学、晶粉衍射以及材料特性等材料科学研究领域的主要课题。 Materials Studio采用了大家非常熟悉Microsoft标准用户界面，它允许你通过各种控制面板直接对计算参数和计算结构进行设置和分析。模块简介：基本环境 MS.Materials Visualizer 分子力学与分子动力学 MS.DISCOVER https://www.wendangku.net/doc/4f11202587.html,PASS MS.Amorphous Cell MS.Forcite MS.Forcite Plus MS.GULP MS.Equilibria MS.Sorption晶体、结晶与X射线衍射 MS.Polymorph Predictor MS.Morphology MS.X-Cell MS.Reflex MS.Reflex Plus MS.Reflex QPA量子力学 MS.Dmol3 MS.CASTEP MS.NMR CASTEP MS.VAMP高分子与介观模拟 MS.Synthia

元素符号表

第02 号元素: 氦[化学符号]He, 读“亥”, [英文名称]Helium 第03 号元素: 锂[化学符号]Li, 读“里”, [英文名称]Lithium 第04 号元素: 铍[化学符号]Be, 读“皮”, [英文名称]Beryllium 第05 号元素: 硼[化学符号]B, 读“朋”, [英文名称]Boron 第06 号元素: 碳[化学符号]C, 读“炭”, [英文名称]Carbon 第07 号元素: 氮[化学符号]N, 读“淡”, [英文名称]Nitrogen 第08 号元素: 氧[化学符号]O, 读“养”, [英文名称]Oxygen 第09 号元素: 氟[化学符号]F, 读“弗”, [英文名称]Fluorine 第10 号元素: 氖[化学符号]Ne, 读“乃”, [英文名称]Neon 第11 号元素: 钠[化学符号]Na, 读“纳”, [英文名称]Sodium 第12 号元素: 镁[化学符号]Mg, 读“美”, [英文名称]Magnesium 第13 号元素: 铝[化学符号]Al, 读“吕”, [英文名称]Aluminum 第14 号元素: 硅[化学符号]Si, 读“归”, [英文名称]Silicon 第15 号元素: 磷[化学符号]P, 读“邻”, [英文名称]Phosphorus 第16 号元素: 硫[化学符号]S, 读“流”, [英文名称]Sulfur 第17 号元素: 氯[化学符号]Cl, 读“绿”, [英文名称]Chlorine 第18 号元素: 氩[化学符号]Ar,A, 读“亚”, [英文名称]Argon 第19 号元素: 钾[化学符号]K, 读“甲”, [英文名称]Potassium 第20 号元素: 钙[化学符号]Ca, 读“丐”, [英文名称]Calcium 第21 号元素: 钪[化学符号]Sc, 读“亢”, [英文名称]Scandium

materials studio介绍资料和案例的应用

新一代材料模拟软件 Materials Studio Accelrys材料科学软件的主要应用领域包括： 固体物理及表面科学 催化、分离与化学反应 高分子及软材料 纳米材料 材料表征与仪器分析 晶体与结晶 QSAR (定量构效关系)与配方设计 Accelrys(美国)公司是世界领先的计算科学公司，是一系列用于科学数据的挖掘、整合、分析、模建与模拟、管理和提交交互式报告的智能软件的开发者，是目前全球范围内唯一能够提供分子模拟、材料设计、化学信息学和生物信息学全面解决方案和相关服务的软件供应商，所提供的全面解决方案和科技服务满足了当今全球领先的研究和开发机构的要求。 Accelrys材料科学软件产品提供了全面和完善的模拟环境，可以帮助研究者构建、显示和分析分子、固体、表面和界面的结构模型，并研究、预测材料的结构与相关性质。Accelrys的软件是高度模块化的集成产品，用户可以自由定制、购买自己的软件系统，以满足研究工作的不同需要。 Accelrys软件用于材料科学研究的主要产品是Materials Studio分子模拟软件，它可以运行在台式机、各类型服务器和计算集群等硬件平台上。Materials Studio分子模拟软件广泛应用在石油、化工、环境、能源、制药、电子、食品、航空航天和汽车等工业领域和教育科研部门；这些领域中具有较大影响的跨国公司及世界著名的高校、科研院所等研究机构几乎都是Accelrys产品的用户。 Materials Studio分子模拟软件采用了先进的模拟计算思想和方法，如量子力学（QM）、线性标度量子力学(Linear Scaling QM)、杂化量子力学分子力学(QM/MM)、分子力学(MM)、分子动力学(MD)、蒙特卡洛(MC)、介观动力学(MesoDyn)和耗散粒子动力学（DPD）、统计方法QSAR(Quantitative Structure-Activity Relationship )等多种先进算法和X射线衍射分析等仪器分析方法；模拟的内容包括了催化剂、聚合物、固体及表面、界面、晶体与衍射、化学反应等材料和化学研究领域的主要课题。 Materials Studio分子模拟软件支持32与64位Windows和Linux操作平台，而且界面非常友好、操作简便，使化学及材料科学的研究者们能更方便地建立三维结构模型，并对各种小分子、晶体、无定型以及高分子材料的性质及相关过程进行深入的研究，得到切实可靠的数据。 Materials Studio软件使任何研究者都能得到和世界一流研究部门相一致的材料模拟技术。

高分子材料常用专业术语中英对照表分析

加工processing 反应性加工reactive processing 等离子体加工plasma processing 加工性processability 熔体流动指数melt [flow] index 门尼粘度Mooney index 塑化plasticizing 增塑作用plasticization 内增塑作用internal plasticization 外增塑作用external plasticization 增塑溶胶plastisol 增强reinforcing 增容作用compatibilization 相容性compatibility 相溶性intermiscibility 生物相容性biocompatibility 血液相容性blood compatibility 组织相容性tissue compatibility 混炼milling, mixing 素炼mastication 塑炼plastication 过炼dead milled 橡胶配合rubber compounding 共混blend 捏和kneading 冷轧cold rolling 压延性calenderability 压延calendaring 埋置embedding 压片performing 模塑molding 模压成型compression molding 压缩成型compression forming 冲压模塑impact moulding, shock moulding 叠模压塑stack moulding 复合成型composite molding 注射成型injection molding 注塑压缩成型injection compression molding 射流注塑jet molding 无流道冷料注塑runnerless injection molding 共注塑coinjection molding 气辅注塑gas aided injection molding 注塑焊接injection welding 传递成型transfer molding

化学元素中英文对照

第 01 号元素: 氢 H [英文名称]Hydrogen 第 02 号元素: 氦 He [英文名称]Helium 第 03 号元素: 锂 Li [英文名称]Lithium 第 04 号元素: 铍 Be [英文名称]Beryllium 第 05 号元素: 硼 B [英文名称]Boron 第 06 号元素: 碳 C [英文名称]Carbon 第 07 号元素: 氮 N [英文名称]Nitrogen 第 08 号元素: 氧 O [英文名称]Oxygen 第 09 号元素: 氟 F [英文名称]Fluorine 第 10 号元素: 氖 Ne [英文名称]Neon 第 11 号元素: 钠 Na [英文名称]Sodium 第 12 号元素: 镁 Mg [英文名称]Magnesium 第 13 号元素: 铝 Al [英文名称]Aluminum 第 14 号元素: 硅 Si [英文名称]Silicon 第 15 号元素: 磷 P [英文名称]Phosphorus 第 16 号元素: 硫 S [英文名称]Sulfur 第 17 号元素: 氯 Cl [英文名称]Chlorine 第 18 号元素: 氩 Ar [英文名称]Argon 第 19 号元素: 钾 K [英文名称]Potassium 第 20 号元素: 钙 Ca [英文名称]Calcium 第 21 号元素: 钪 Sc [英文名称]Scandium 第 22 号元素: 钛 Ti [英文名称]Titanium 第 23 号元素: 钒 V [英文名称]Vanadium 第 24 号元素: 铬 Cr [英文名称]Chromium 第 25 号元素: 锰 Mn [英文名称]Manganese 第 26 号元素: 铁 Fe [英文名称]Iron 第 27 号元素: 钴 Co [英文名称]Cobalt 第 28 号元素: 镍 Ni [英文名称]Nickel 第 29 号元素: 铜 Cu [英文名称]Copper 第 30 号元素: 锌 Zn [英文名称]Zinc 第 31 号元素: 镓 Ga [英文名称]Gallium 第 32 号元素: 锗 Ge [英文名称]Germanium 第 33 号元素: 砷 As [英文名称]Arsenic 第 34 号元素: 硒 Se [英文名称]Selenium 第 35 号元素: 溴 Br [英文名称]Bromine 第 36 号元素: 氪 Kr [英文名称]Krypton 第 37 号元素: 铷 Rb [英文名称]Rubidium 第 38 号元素: 锶 Sr [英文名称]Strontium 第 39 号元素: 钇 Y [英文名称]Yttrium 第 40 号元素: 锆 Zr [英文名称]Zirconium 第 41 号元素: 铌 Nb [英文名称]Niobium 第 42 号元素: 钼 Mo [英文名称]Molybdenum 第 43 号元素: 锝 Tc [英文名称]Technetium 第 44 号元素: 钌 Ru [英文名称]Ruthenium 第 45 号元素: 铑 Rh [英文名称]Rhodium 第 46 号元素: 钯 Pd [英文名称]Palladium 第 47 号元素: 银 Ag [英文名称]Silver 第 48 号元素: 镉 Cd [英文名称]Cadmium 第 49 号元素: 铟 In [英文名称]Indium 第 50 号元素: 锡 Sn [英文名称]Tin 第 51 号元素: 锑 Sb [英文名称]Antimony 第 52 号元素: 碲 Te [英文名称]Tellurium 第 53 号元素: 碘 I [英文名称]Iodine 第 54 号元素: 氙 Xe [英文名称]Xenon 第 55 号元素: 铯 Cs [英文名称]Cesium 第 56 号元素: 钡 Ba [英文名称]Barium 第 57 号元素: 镧 La [英文名称]Lanthanum 第 58 号元素: 铈 Ce [英文名称]Cerium 第 59 号元素: 镨 Pr [英文名称]Praseodymium 第 60 号元素: 钕 Nd [英文名称]Neodymium 第 61 号元素: 钷 Pm [英文名称]Promethium 第 62 号元素: 钐 Sm [英文名称]Samarium

materialstudio使用经验总结

materialstudio 使用经验总结 关于K 点 1.应当使用多少个k 网格? 很难一般地回答,只能给出一般建议。注意:一定要检查k 网格,首先用较粗糙的网格计算, 接下来用精细的网格计算。通过比较两次的结果, 决定选用较粗糙的网格, 或是继续进行更 精细网格的计算, 直到达到收敛。金属体系需要精细的网格, 绝缘体使用很少的k 点通常就 可以。小单胞需要精细格点, 大单胞很可能不需要。因此: 单位晶胞内原子数很多（比如 40-60个）的绝缘体,可能仅需要一个（移动后的）k点。另一方面,面心立方的铝可能需 要上万个k点以获得好的DOS对于孤立原子或分子的超晶胞，仅需要在 Gamm点计算。对 于表面（层面）的超晶胞计算,仅需要（垂直于表面）z方向上有1个k点。甚至可以增加 晶格参数c,这样即使对精细格点，沿z方向上也只产生一个k点（产生k 点后, 不要忘记 再把 c 改回）。

2.当体系没有出现时间反演对称操作时, 是否加入? 大多数情况下的回答是“是” , 只有包含自旋- 轨道耦合的自旋极化（磁性）计算除外。这 时, 时间反演对称性被破坏（+k 和-k 的本征值可能不同）, 因此决不能加入时间反演对称性。 3.是否移动k 网格?（只对某些格子类型有效） “移动” k网格意味着把所有产生的k点增加x,x,x,把那些位于高对称点（或线）上的k 点移动到权重更大的一般点上。通过这种方法（也即众所周知的“特殊k 点方法” ）可以产 生等密度的,k 点较少的网格。通常建议移动。只有一点注意: 当对半导体的带隙感兴趣时 （通常位于Gamma,X或BZ边界上的其它点）,使用移动的网格将不会得到这些高对称性 的点,因此得到的带隙和预期结果相比或大或小。这个问题的解决:用移动的网格做SCF 循环，但对DOS计算，改用精细的未移动网格。 关于k 空间布点的问题, 建议参阅以下文献Phys.Rev.B 49,16223 1994 如何构建缺陷晶体结构 晶体结构改成P1, 然后去掉想抹去的原子就可以了 在ms中如何做空穴 对于金属缺陷, 是直接剪切一个原子?