阅读说明：本技术 一种湿陷性黄土地层中海绵城市道路分级排水系统 (Sponge urban road grading drainage system in collapsible loess stratum ) 是由 佘芳涛 吴征奇 周庆怡 周伟踪 张彬 付炜烨 张赛赛 刘乐乐 于 2021-10-21 设计创作，主要内容包括：本发明公开了一种湿陷性黄土地层中海绵城市道路分级排水系统,包括路缘调蓄箱,路缘调蓄箱设于路面与绿化带交界处,路缘调蓄箱靠近绿化带的侧面开口与一级排水管相连,隔水墙设于路缘调蓄箱下部,两隔水墙中间由上至下依次设有植被种植层、碎石层、灰土垫层和防渗膜,渗流箱位于灰土垫层内,渗流箱靠近道路方向的侧面自下而上设有两开口分别与二级排水管、三级排水管相连,且二级排水管、三级排水管皆穿过隔水墙至道路侧边缘,二级排水管接入雨水井或市政管网,三级排水管通过直角弯头接入位于隔水墙外侧、埋设于道路下方的导水砂井,透水管沿道路纵向设于靠近碎石层中间下部。能够有效排除路面积水,适用范围广,可避免道路发生破坏。(The invention discloses a sponge urban road graded drainage system in a collapsible yellow land layer, which comprises a curb storage box, wherein the curb storage box is arranged at the junction of a road surface and a green belt, a side opening of the curb storage box close to the green belt is connected with a primary drainage pipe, a water-stop wall is arranged at the lower part of the curb storage box, a vegetation planting layer, a gravel layer, an ash soil cushion layer and an impermeable membrane are sequentially arranged between the two water-stop walls from top to bottom, a seepage box is positioned in the ash soil cushion layer, two openings are arranged on the side surface of the seepage box close to the road direction from bottom to top and are respectively connected with a secondary drainage pipe and a tertiary drainage pipe, and the second-level drain pipe and the third-level drain pipe penetrate through the water-stop wall to the edge of the road side, the second-level drain pipe is connected into the rainwater well or the municipal pipe network, the third-level drain pipe is connected into the water-guiding sand well which is positioned on the outer side of the water-stop wall and buried under the road through a right-angle elbow, and the water-permeable pipe is longitudinally arranged on the lower portion of the middle of the gravel layer along the road. Can effectively get rid of surface gathered water, application scope is wide, can avoid the road to take place to destroy.)

1. The utility model provides a hierarchical drainage system of sponge urban road in collapsible loess stratum, a serial communication port, including curb regulation case (1), diaphragma (4), seepage flow case (12), pipe (11) of permeating water, road surface and greenbelt juncture are located in curb regulation case (1), curb regulation case (1) is close to the side opening of greenbelt and links to each other with one-level drain pipe (10), and curb regulation case (1) lower part is located diaphragma (4), is equipped with vegetation planting layer (5), metalling, ash soil cushion (8) and prevention of seepage membrane (9) from top to bottom in the middle of two diaphragma (4) in proper order, and seepage flow case (12) are located ash soil cushion (8), seepage flow case (12) are equipped with two openings from bottom to top and link to each other with second grade drain pipe (10b), tertiary drain pipe (10c) respectively near the side of road direction, and second grade drain pipe (10b), Tertiary drain pipe (10c) all pass water-stop wall (4) to the roadside edge, second grade drain pipe (10b) inserts rainwater well or municipal pipe network (17), tertiary drain pipe (10c) insert through elbow bend (13) lie in water-stop wall (4) outside, bury water guide sand well (14) of burying in the road below, pervious pipe (11) are vertically located along the road and are close to the middle lower part of rubble layer.

2. The graded drainage system for sponge urban roads in collapsible loess strata as claimed in claim 1, wherein: the curb storage box (1) is a cuboid and is arranged along the longitudinal whole course of a road, the height of the curb storage box is 30cm, the height of the portion above the ground is 20cm, the lower portion of the ground is 10cm, the portion, which exceeds the road surface, of the side surface of the curb storage box (1) close to the road direction and is below an opening formed in the side surface close to the green belt direction are poured by pervious concrete, and the rest portions are poured by common concrete; curb regulation case (1) are close to the side of road direction and are equipped with trompil (2) along the longitudinal interval of road, and trompil (2) are located 15cm above the road surface, and inside is equipped with double-deck filter screen (3).

3. The graded drainage system for sponge urban roads in collapsible loess strata as claimed in claim 1, wherein: the length of the water-stop wall (4) is equal to that of the curb storage box (1), the water-stop wall is arranged along the longitudinal whole course of the road, and the water-stop wall is arranged from the bottom of the curb storage box (1) to the bottom of the lime soil cushion layer (8).

4. The graded drainage system for sponge urban roads in collapsible loess strata as claimed in claim 1, wherein: the height of one-level drain pipe (10) and curb regulation case (1) side opening junction is the same with the road surface height, and one-level drain pipe (10) pass vegetation planting layer (5) to rubble layer top.

5. The graded drainage system for sponge urban roads in collapsible loess strata as claimed in claim 1, wherein: the gravel layer sets up first gravel layer (6) and second gravel layer (6a) along the road is vertical in turn, and grey soil bed course (8) top is located to the equipartition, and wherein, second gravel layer (6a) thickness is 1/3 of first gravel layer (6) thickness, all is vegetation planting layer (5) more than second gravel layer (6 a).

6. The graded drainage system for sponge urban roads in collapsible loess strata as claimed in claim 1, wherein: the contact surfaces of the gravel layer, the vegetation planting layer (5) and the lime soil cushion layer (8) are all provided with permeable geotextile (7).

7. The graded drainage system for sponge urban roads in collapsible loess strata as claimed in claim 1, wherein: seepage flow box (12) are the cuboid, and vertical interval along the road arranges, adopts the fine aggregate concrete material, and rainwater in seepage flow box (12) earlier discharges catch basin or municipal pipe network (17) through second grade drain pipe (10b), and when the incasement water level rose to the take the altitude, the rainwater was through tertiary drain pipe (10c) leading-in vertical water guide sand pit (14).

8. The graded drainage system for sponge urban roads in collapsible loess strata as claimed in claim 1, wherein: the water guide sand well (14) is excavated to a position below a soil layer boundary layer (16), a PVC anti-seepage cylinder (15) is sunk along the well wall, and sand is filled in the anti-seepage cylinder (15).

9. The graded drainage system for sponge urban roads in collapsible loess strata as claimed in claim 1, wherein: the pipe (11) top of permeating water evenly is equipped with trompil (2) in little aperture with pipe week upper half interval, and gravel layer bottom intermediate position is located in pipe (11) of permeating water of first gravel layer (6), and large aperture trompil (2) are established to the bottom, are located the pipe (11) portion of permeating water of second gravel layer (6a), and trompil (2) are not established to the bottom.

10. The graded drainage system for sponge urban roads in collapsible loess strata as claimed in claim 1, wherein: the perforated pipe (2) at the bottom of the water permeable pipe (11) is connected with one end of a drainage connecting pipe (10a), the other end of the drainage connecting pipe (10a) is connected into the top opening of the seepage box (12), the part of the water permeable pipe (11) located on the second gravel layer (6a) is not provided with the drainage connecting pipe (10a) and the subsequent drainage structure of the seepage box (12).

Technical Field

The invention relates to the technical field of sponge city construction, in particular to a graded drainage system for a sponge city road in a collapsible loess stratum.

Background

Along with the high-speed development of economy, the contradiction of serious shortage of water resources, serious water ecological pollution problem, uneven water resource space-time distribution and the like in China is increasingly prominent, and huge hidden dangers are brought to city management and people safety. The problems of waterlogging, heat island effect, water pollution, overwhelming drainage pipe network and the like of the city caused by 'waterlogging when raining and drought after raining', and a set of system is urgently needed to solve the influence caused by disasters, so that the sponge city can develop the rainwater system with low influence and can be transported. The sponge city, as the name suggests just builds the city into a "cavernosum", full play its absorb water, infiltration, stagnant water, retaining, water purification drainage and water use function, play the effect such as flood storage drainage, water resources are kept in good care, rain sewage purifies and replenish groundwater, solve the problem from the source, can improve water resource utilization and effectively alleviate city flood calamity.

The proportion of roads in urban construction is large, particularly motor vehicle lanes, the requirement on the strength of the roads is high, the strength is difficult to meet when pervious concrete is adopted, so that the roads are mostly hardened pavements, and road water accumulation is easily caused during rainstorm. The non-permeable pavement greatly increases the drainage pressure and surface runoff of a city, and the road is seriously polluted by traffic, so that a sponge city needs to be reasonably utilized, a road drainage system is scientifically designed, and the harmonious development of nature and the city is promoted.

The collapsible loess foundation is soaked in water under certain pressure, and has fast destruction, low strength, great settlement, inclination and cracking of the roadbed and high use performance. In the construction of sponge urban roads in collapsible loess strata, the harm caused by collapsible nature needs to be fully considered, and at present, no effective scheme for the construction of sponge urban road drainage systems exists in the collapsible loess strata.

Chinese patent application CN 213296166U discloses a sponge urban road green median, which comprises a gravel layer, a fine sand layer, an artificial packing layer, a soil planting layer, a gravel layer and a water-absorbing piece, wherein the rainwater purified and stored in the gravel layer is transported by the water-absorbing piece for plants, thereby improving the utilization rate of the rainwater and reducing the road ponding. The following problems still remain: 1) the water drawing device has a simple structure, the service life of the water drawing piece is not long, once the water drawing piece is damaged, the arrangement of the whole green belt can not play a role so as to realize the recycling of water resources, the water drawing device is divided into three layers, green belt vegetation is irrigated, rainwater is discharged into a municipal pipe network and deep water guide, the three layers are mutually independent, and the system stability is better; 2) the gravel layer is laid under the root system of the vegetation, which is not beneficial to the growth of the root system of the vegetation, especially for plants with deeper root systems such as trees, and the invention is provided with a vegetation planting layer, the gravel layers are laid under the vegetation planting layer, and the gravel layers with different thicknesses are alternately arranged along the longitudinal direction of the road, so that the plants with different root system depths can be planted respectively; 3) the invention only has the functions of absorbing, permeating, stagnating, storing, purifying, draining and using water, and cannot meet the drainage requirement of the sponge urban road in the collapsible loess stratum, and the invention is additionally provided with the functions of water isolation and water guide.

Chinese patent application CN 108999056 a discloses sponge urban road rainwater integration circulation processing system, including rainwater collection unit, rainwater processing unit and rainwater utilization unit, the rainwater is abandoned class through the initial stage earlier, utilizes membrane biological reaction pond to purify afterwards, passes through sensor control sprinkler at last, realizes the utilization of rainwater. However, two problems still exist: 1) the system is too complex in structure, the difficulty of the rainwater circulating collection and treatment device in underground facility arrangement is large, the road is paved in a permeable way, the subgrade is damaged by the wet collapse, and the system is not suitable for the loess area, the road of the system has a certain gradient to flow to a green belt to collect rainwater on the basis of hardening the road surface, the system is arranged near the green belt to remove the accumulated water on the road surface, and the wet collapse of the loess is fully considered; 2) only collect, handle and discharge into municipal pipe network through the rainwater and be not enough to deal with bad weather, municipal pipe network pressure is great when rainstorm, can't fully get rid of surface ponding.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a grading drainage system for sponge urban roads in a collapsible loess stratum.

(II) technical scheme

In order to achieve the purpose, the invention provides the following technical scheme: a graded drainage system for sponge urban roads in collapsible loess strata comprises a curb storage box, a water-stop wall and a seepage box, wherein the curb storage box is arranged at the junction of a road surface and a green belt, a side opening of the curb storage box close to the green belt is connected with a first-level drainage pipe, the water-stop wall is arranged at the lower part of the curb storage box, a vegetation planting layer, a gravel layer, an ash soil cushion layer and an anti-seepage film are sequentially arranged between the two water-stop walls from top to bottom, the seepage box is positioned in the ash soil cushion layer, two openings are arranged at the side of the seepage box close to the road direction from bottom to top and are respectively connected with a second-level drainage pipe and a third-level drainage pipe, the second-level drainage pipe and the third-level drainage pipe all penetrate through the water-stop wall to the road side edge, the second-level drainage pipe is connected with a rainwater well or a municipal pipe network, the third-level drainage pipe is connected with a water guiding sand well which is positioned outside the water-stop wall and is buried under the road through a right-angle elbow, the water permeable pipe is longitudinally arranged near the middle lower part of the gravel layer along the road.

Preferably, the curb storage box is a cuboid and is arranged along the longitudinal whole course of the road, the height of the curb storage box is 30cm, the height of the portion above the ground is 20cm, the portion below the ground is 10cm, the portion, below an opening, of the side surface of the curb storage box close to the road direction, which exceeds the road surface portion and is close to the green belt direction is poured by pervious concrete, and the rest portions are poured by common concrete; curb regulation case is close to the side of road direction and is equipped with the trompil along the longitudinal interval of road, and the trompil is located 15cm above the road surface, and inside is equipped with double-deck filter screen.

Preferably, the length of the water-stop wall is equal to that of the curb storage box, the water-stop wall is arranged along the longitudinal whole course of the road, and the height of the water-stop wall is from the bottom of the curb storage box to the bottom of the lime soil cushion layer.

Preferably, the height of one-level drain pipe and curb regulation and storage case side opening junction is the same with the road surface height, and the one-level drain pipe passes vegetation planting layer to rubble layer top.

Preferably, the rubble layer sets up first rubble layer and second rubble layer along the vertical alternation of road, and the lime soil bed course top is located to the equipartition, and wherein, second rubble layer thickness is 1/3 of first rubble layer thickness, all is the vegetation planting layer more than the second rubble layer.

Preferably, the contact surfaces of the gravel layer, the vegetation planting layer and the lime soil cushion layer are all provided with permeable geotextile.

Preferably, the seepage flow box is the cuboid, arranges along the vertical interval of road, adopts the fine aggregate concrete material, and rainwater in the seepage flow box is earlier through second grade drain pipe row rainwater well or municipal pipe network, and when the incasement water level rose to a take the altitude, the rainwater flowed in vertical water guide sand pit through tertiary drain pipe.

Preferably, the water guide sand well is excavated to a position below a soil layer boundary layer, a PVC anti-seepage cylinder is sunk along the well wall, and sand is filled in the anti-seepage cylinder.

Preferably, the pipe top of permeating water and the pipe half interval on week evenly are equipped with the trompil in aperture, and the pipe of permeating water locates gravel layer bottom intermediate position, is located the intraformational pipe portion of permeating water of first rubble, and the aperture trompil is established to the bottom, is located the intraformational pipe portion of permeating water of second rubble, and the trompil is not established to the bottom.

Preferably, the open pore of the bottom of the permeable pipe is connected with one end of a drainage connecting pipe, the other end of the drainage connecting pipe is connected into the top opening of the seepage box and is positioned in the permeable pipe part of the second gravel layer, and the bottom of the permeable pipe is not provided with a drainage connecting pipe, the seepage box and other subsequent drainage structures.

(III) advantageous effects

The invention provides a grading drainage system for sponge urban roads in a collapsible loess stratum. The method has the following beneficial effects: the invention provides a sponge urban road graded drainage system suitable for a collapsible loess stratum, which is used for removing road accumulated water in three mutually independent stages, is suitable for light rain, medium rain, heavy rain and even heavy rain, and is additionally provided with a lime soil cushion layer, an impermeable film and a water-proof wall for water insulation and a vertical water-guiding sand well for water guiding on the basis of water absorption, permeation, stagnation, storage, purification, drainage and use in a sponge city, so that water can be effectively prevented from permeating into the collapsible stratum, and the loess roadbed is prevented from being collapsed and damaged. The system can realize graded drainage: firstly, the rainwater storage tank can absorb initial rainwater to irrigate plants on the vegetation planting layer, the plants can play roles of purified water and stagnant water, and when the water amount is too large, on one hand, rainwater can permeate into the gravel layer through the vegetation planting layer, and on the other hand, rainwater can directly flow into the gravel layer through the primary water drainage pipe; secondly, the rainwater filtered by the crushed stone layer can be discharged into a rainwater well or a municipal pipe network; thirdly, when the rainfall is too big, in order to prevent that the ground from taking place the collapsible destruction and municipal pipe network pressure is too big, the accessible water guide sand well is with the leading-in non-collapsible stratum of rainwater. The invention is stable and reliable, can effectively discharge accumulated water on the road surface, has wide application range and can avoid the damage of the road.

Drawings

FIG. 1 is a schematic overall structure of the present invention;

FIG. 2 is a cross-sectional view of a subterranean formation according to the present invention;

FIG. 3 is a longitudinal cross-sectional view of the present invention;

FIG. 4 is a schematic view of the connection between the permeable pipe and the infiltration tank of the present invention.

In the figure, 1, a curb storage box, 2, holes, 3, a filter screen, 4, a water-stop wall, 5, a vegetation planting layer, 6, a first gravel layer, 6a, a second gravel layer, 7, permeable geotextile, 8, a lime soil cushion layer, 9, an impermeable membrane, 10, a first-stage drain pipe, 10a, a drainage connecting pipe, 10b, a second-stage drain pipe, 10c, a third-stage drain pipe, 11, a permeable pipe, 12, a seepage box, 13, a right-angle elbow, 14, a water-guiding sand well, 15, an impermeable cylinder, 16, a soil layer boundary layer and 17, a rainwater well or a municipal pipe network.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1 to 4, the present invention provides a technical solution: a graded drainage system for sponge urban roads in collapsible loess strata, which comprises a curb storage tank 1, the curb storage box 1 is arranged at the junction of the road surface and the green belt, an opening at one side of the curb storage box 1 close to the green belt is connected with a primary drain pipe 10, the water-stop walls 4 are arranged at the lower part of the curb storage box 1, a vegetation planting layer 5, a gravel layer, a lime soil cushion layer 8 and an impermeable membrane 9 are sequentially arranged between the two water-stop walls 4 from top to bottom, the seepage box 12 is positioned in the lime soil cushion layer 8, the side surface of the seepage box 12 close to the road direction is provided with two openings from bottom to top which are respectively connected with a secondary drainage pipe 10b and a tertiary drainage pipe 10c, and both pipes pass through the water-stop wall 4 to the side edge of one side of the road, the secondary drainage pipe 10b is connected to a catch basin or municipal pipe network 17, the third-stage drainage pipe 10c is connected to a water guide sand well 14 which is positioned outside the water separation wall 4 and buried below a road through a right-angle elbow 13;

the water permeable pipes 11 are longitudinally arranged near the lower part of the middle of the gravel layer along a road so as to collect rainwater filtered by the gravel layer, the top parts and the upper half parts of the peripheries of the water permeable pipes 11 are uniformly provided with the open holes 2 at intervals, the water permeable pipes 11 are arranged in the middle of the bottom of the gravel layer, the water permeable pipes 11 positioned in the first gravel layer 6 are provided with the open holes 2 at the bottom, the water permeable pipes 11 positioned in the second gravel layer 6a are provided with no open holes 2 at the bottom;

one end of the drainage connecting pipe 10a is connected with the open pore 2 at the bottom of the permeable pipe 11, the other end is connected with the top opening of the seepage box 12, the drainage connecting pipe 10a and the seepage box 12 are not arranged at the bottom of the permeable pipe 11 part of the second gravel layer 6a.

Furthermore, the curb storage box 1 is a cuboid and is arranged along the longitudinal whole course of the road, the height of the curb storage box is 30cm, the height of the portion above the ground is 20cm, the height of the portion below the ground is 10cm, the portion, close to the road, of the side surface of the box body is higher than the road surface, the portion, close to the side surface of the green belt, below the opening is poured by pervious concrete, the rest portions are poured by common concrete, and the curb storage box 1 can play a role in adjusting and distributing rainwater.

Furtherly, 1 sides of curb regulation case that is close to the road direction are equipped with trompil 2 along the longitudinal interval of road, and surface ponding is more, and when the concrete part of permeating water did not reach to get rid of ponding, the rainwater flows into the box through 2 trompils that the aperture is big, and trompil 2 is located 15cm above the road surface department, and inside is equipped with double-deck filter screen 3, intercepts great debris such as branches and leaves, rubbish.

Further, the length of the water-stop wall 4 is equal to that of the curb storage box 1, the water-stop wall is arranged along the longitudinal whole course of the road, and the water-stop wall is arranged from the bottom of the curb storage box 1 to the bottom of the lime soil cushion layer 8, so that the water in the green belt can be prevented from permeating the roads on two sides to cause the damage of the wet fall.

Further, the height and the road surface height of one-level drain pipe 10 and 1 side opening junction of curb regulation case are the same, make the rainwater of regulation incasement satisfy the vegetation and plant 5 required backs in layer, can in time discharge through one-level drain pipe 10, avoid the rainwater accumulation too much to flow back to the road surface, and one-level drain pipe 10 passes vegetation and plants 5 to rubble layer tops, emits into the rubble layer with the rainwater.

Further, the rubble layer sets up first rubble layer 6 and second rubble layer 6a along the vertical turn of road, 8 tops in the lime soil bed course are located to the equipartition, and wherein, second rubble layer 6a thickness is 1/3 of first rubble layer 6 thickness, all be vegetation planting layer 5 more than the second rubble layer 6a for the different plant of root system degree of depth can be planted along the road green belt line, plant the layer 5 selective plant that the root system is lighter if lie in vegetation planting on first rubble layer 6, like ground quilt class, and lie in vegetation planting layer 5 on second rubble layer 6a, because rubble layer thickness is little, soil planting layer thickness is big, can plant the darker arbor class of root system and bush class etc..

Furthermore, all be equipped with the geotechnological cloth 7 that permeates water on the contact surface of rubble layer and vegetation planting layer 5, grey soil bed course 8, make the tiny particle such as soil and silt can not get into seepage flow box 12 through the rubble layer, play the filtering action.

Further, the diaphragm wall 4 can prevent that the rainwater from to the collapsible stratum of both sides infiltration road below, the collapsible stratum of rainwater infiltration to greenbelt below can be avoided to lime soil bed course 8 and prevention of seepage membrane 9, and the water proof effect through diaphragm wall 4, lime soil bed course 8 and prevention of seepage membrane 9 can be avoided the collapsible loess stratum to take place the collapsible destruction.

Further, seepage case 12 is the cuboid, arranges along road longitudinal separation, adopts the fine aggregate concrete material, and rainwater in the seepage case 12 passes through second grade drain pipe 10b earlier and discharges into catch basin or municipal pipe network 17, and when the rainfall is great, incasement water level rises to a take the altitude, and the rainwater flows in vertical water guide sand well 14 through tertiary drain pipe 10c, accomplishes deep water guide, seepage case 12 can adjust, alleviate municipal pipe network pressure when the rainfall is great, makes the road drainage unobstructed, can establish the sponge city better.

Furthermore, the water guide sand well 14 is excavated below a soil layer boundary layer 16, a PVC anti-seepage cylinder 15 sinks along the well wall, sand is filled in the anti-seepage cylinder 15, and the water guide sand well has good water guide performance and can guide part of rainwater into a non-collapsible stratum.

Example (b): in the rainfall, the invention is divided into three stages of drainage. Firstly, as the hardened road surface is in a certain slope, rainwater is collected to the outer side of the curb storage box 1 and enters the box body from the permeable concrete on the side (which can pass through the opening 2 when the rainfall is large), and the rainwater in the box initially permeates into the vegetation planting layer 5 through the permeable concrete on the inner side; secondly, along with the rise of the water level in the box, rainwater flows into the gravel layer through the primary water discharge pipe 10, is collected through the water permeable pipe 11 in the gravel layer and is conveyed to the seepage box 12, and the rainwater in the seepage box 12 can be discharged into a rainwater well or a municipal pipe network 17 through the secondary water discharge pipe 10b when the water quantity is small and the water level is low; thirdly, when rainstorm or continuous rainfall occurs, the water level in the seepage box 12 rises to the interface of the three-level drainage pipe 10c, the three-level drainage pipe 10c is connected into the vertical water guiding sand well 14, and rainwater is guided into the lower part of the soil layer boundary layer 16, so that graded drainage of the road is realized. Meanwhile, the lime soil cushion layer, the impermeable film and the water-stop wall can play a water-stop role, and rainwater can be effectively prevented from permeating a collapsible stratum.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.