Subgrade irrigation for site preparation having clayey expansive soil

Patent metadata

Field	Value
Publication number	US-2018265783-A1
Application number	US-201815939658-A
Country	US
Kind code	A1
Filing date	Mar 29, 2018
Priority date	Dec 23, 2015
Publication date	Sep 20, 2018
Grant date	—

Abstract

A method of reducing the swell potential of an expansive clayey soil comprising expansive clay mineral(s) at a proportion of the total weight of the expansive clayey soil (P ECM ). The method includes (a) calculating a first amount of a swelling reduction agent to be incorporated into the expansive clayey soil to form a first swelling reduction agent incorporated expansive clayey soil with a reduced swell potential no greater than a pre-set level T with a nano-level constitutive modeling based on the water content and the CEC of the expansive clayey soil and P ECM . The swelling reduction agent is at least one selected from calcite, gypsum, potassium chloride, a composition comprising exchangeable K + , a composition comprising exchangeable Ca 2+ , and/or a composition comprising exchangeable Mg 2+ , and (b) incorporating the first amount of the swelling reduction agent into the expansive clayey soil to form the first swelling reduction agent incorporated expansive clayey soil.

First claim

1 - 10 . (canceled)

11 . A method of preparing a site having a reduced swell potential of an expansive clayey soil at the site, wherein the expansive clayey soil comprises comprising at least one expansive clay mineral, the proportion of the weight of the at least one expansive clay mineral relative to the total weight of the expansive clayey soil being P ECM , the expansive clayey soil having a first water content and a cation exchange capacity (CEC) expressed in meq/100 g dry expansive clayey soil, the method comprising:
(a) determining a second water content of a wetted expansive clayey soil to be formed by wetting the expansive clayey soil with water, the wetted expansive clayey soil having a reduced swell potential S w(soil) that is no greater than a pre-set level T in accordance with a nano-level constitutive modeling based on the cation exchange capacity (CEC) of the expansive clayey soil and the second water content of the wetted expansive clayey soil as an initial water content (IWC), wherein the wetted expansive clayey soil comprises wetted at least one expansive clay mineral having the second water content and a swell potential S w(ECM) , wherein the second water content as the initial water content (IWC) is greater than the first water content but no greater than a final water content (FWC) of the at least one expansive clay mineral when the at least one expansive clay mineral reaches the swell potential, and produces a modified total cohesive energy density (TCEDm) of the wetted at least one expansive clay mineral calculated according to Equation (6) whether or not the expansive clayey soil further comprises at least one selected from the group consisting of calcite, gypsum, potassium chloride, calcium exchangeable cation, magnesium exchangeable cation, and potassium exchangeable cation:
TCED m= 0.0625(IWC) 3 −3.575(IWC) 2 +10.5(IWC)+2830+7100(C/0.1)+5050( G/ 0.2)+3010(KCl/0.1)+Ca(500)+Mg(300)+K(100)   (6)

where TCEDm=modified TCED, C=Proportion of calcite weight relative to the total weight of the expansive clayey soil×P ECM , G=Proportion of gypsum weight relative to the total weight of the expansive clayey soil×P ECM , KCl=Proportion of potassium chloride weight relative to the total weight of the expansive clayey soil×P ECM , Ca=Proportion of the number of calcium exchangeable cation relative to the total number of exchangeable cations in the expansive clayey soil, Mg=Proportion of the number of magnesium exchangeable cation relative to the total number of exchangeable cations in the expansive clayey soil, K=Proportion of the number of potassium exchangeable cation relative to the total number of exchangeable cations in the expansive clayey soil, IWC=initial water content, wherein the TCEDm of the wetted at least one expansive clay mineral results in S w(ECM) calculated according to Equations (2), (3), and (5):
IDD={−2 E− 15(TCED m ) 4 +5 E− 11(TCED m ) 3 −5 E− 07(TCED m ) 2 +0.0023(TCED m )−1.5378}*1.85*(ABS(CEC−90)/90)   (2)

where IDD is initial dry density of the wetted at least one expansive clay mineral,
FDD=−2 E− 22(TCED m ) 6 +5 E− 18(TCED m ) 3 −6 E− 14(TCED m ) 4 +3 E− 10(TCEDm) 3 −7 E− 07(TCED m ) 2 +0.0005(TCED m )+0.3747   (3)

where FDD is final dry density of the wetted at least one expansive clay mineral when the wetted at least one expansive clay mineral reaches the swell potential S w(ECM) ,
S w(ECM) (%)=(FDD−IDD)/FDD*100   (5); and

wherein the reduced swell potential of the wetted expansive clayey soil S w(soil ) equals S w(ECM) ×P ECM , and (b) installing pipes at the site in the expansive clayey soil having the first water content, wherein the pipes have injection points for injecting water into the expansive clayey soil having the first water content, (c) subgrade irrigating the expansive clayey soil having the first water content at the site with water to form the wetted expansive clayey soil having the second water content.

12 . The method of claim 11 , further comprising calculating the final water content (FWC) of the at least one expansive clay mineral when the at least one expansive clay mineral reaches the swell potential with the nano-level constitutive modeling based on the first water content as an initial water content (IWC) and the cation exchange capacity (CEC) of the expansive clayey soil,
wherein the at least one expansive clay mineral has a modified total cohesive energy density (TCEDm) calculated according Equation (6) whether or not the expansive clayey soil further comprises at least one selected from the group consisting of calcite, gypsum, potassium chloride, calcium exchangeable cation, magnesium exchangeable cation, and potassium exchangeable cation:
TCED m= 0.0625(IWC) 3 −3.575(IWC) 2 +10.5(IWC)+2830+7100(C/0.1)+5050(G/0.2)+3010(KCl/0.1)+Ca(500)+Mg(300)+K(100)   (6)

where TCEDm=modified TCED, C=Proportion of calcite weight relative to the total weight of the expansive clayey soil×P ECM , G=Proportion of gypsum weight relative to the total weight of the expansive clayey soil×P ECM , KCl=Proportion of potassium chloride weight relative to the total weight of the expansive clayey soil×P ECM , Ca=Proportion of the number of calcium exchangeable cation relative to the total number of exchangeable cations in the expansive clayey soil, Mg=Proportion of the number of magnesium exchangeable cation relative to the total number of exchangeable cations in the expansive clayey soil, K=Proportion of the number of potassium exchangeable cation relative to the total number of exchangeable cations in the expansive clayey soil, IWC=initial water content, and wherein the TCEDm of the at least one expansive clay mineral results in the final water content (FWC) of the at least one expansive clay mineral when the at least one expansive clay mineral reaches the swell potential according to Equation (4):
FWC={1 E− 13(TCED m ) 4 −4 E− 09(TCED m ) 3 +4 E− 05(TCED m ) 2 −0.2037TCED m+ 369.54 }*ABS ( CEC 2 −90)/CEC 2 *0.82   (4)

13 - 20 . (canceled)

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Ahmed Habib Ur-Rehman
• Abduljauwad Sahel Nishat

Classifications

• B09C2101/00

  In situ · CPC title

• B09C1/08

  chemically · CPC title

• C04B33/131

  Inorganic additives · CPC title

• C09K17/02

  containing inorganic compounds only · CPC title

• A01G25/06

  Watering arrangements making use of perforated pipe-lines located in the soil · CPC title