00_31_32-1_3_A_1_g_20170320 Inclinometer Readings.pdf

Arcadis U.S., Inc.

10352 Plaza Americana Drive

Baton Rouge

Louisiana 70816

Tel 225 292 1004

Fax 225 218 9677

Page:

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MEMO

To:

Edgar Iniguez Contracting Officer Representative

IBWC

Copies:

Padinare Unnikrishna (USIBWC) Armando Flores (Arcadis)

From:

Kirk Lowery, P.E.

Date: Arcadis Project No.:

March 20, 2017 LA003315.0000

Subject:

March 2017 Summary Report of Inclinometer Readings Remediation Design of Levee Floodplain Failure within the Upper Brownsville Levee Reach Lower Rio Grande Flood Control Project – IBM15D0001 – IBM15T0015

1. Introduction

Arcadis U.S., Inc. (Arcadis), is pleased to submit this summary technical memorandum including data charts of the slope inclinometer readings at the IBWC site. The baseline readings for the new inclinometers, ARC- 1, ARC-2, ARC-3 and ARC-4, were taken in June 2016 and the eighth set of readings were measured on March 17, 2017. These inclinometers will be measured every month until early July of 2017.

Exact readings for the existing inclinometers, I-32, I-33 and I-34, were not made when Arcadis visited the site March 17, 2017. However, the probe was placed in the inclinometer casings and the depth at which it would not pass was recorded. Arcadis measured the depth range in which the inclinometer probe could not pass through the constricted area of the pipe and are as follows:

I-32 (Top of the Levee): Depth Range: 32 feet

I-33 (Toe of the Levee): Depth Range: 38 feet to 39 feet

I-34 (Below Toe of Levee): Depth Range: 30 feet to 31 feet

In this month’s visit to the IBWC site, tension cracks were observed on top of the levee near inclinometer ARC-1 and new cracks were discovered south of the existing retaining wall in two sections as shown in Attachment B. At the known surface cracks near ARC-1, there was no displacement with respect to the

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February 8, 2017 measurements for Pin 1 through Pin 6. For the two new cracks that were observed during this month’s visit, Arcadis installed ten additional pin flags along the two cracks to obtain initial measurements. These pin flags mentioned above will be used as a reference to measure over the next four months to observe if the cracks widen or extend either south or north. Table 1 summarized the pin flags location along the cracks.

Table 1. Pin Flag Locations

Pin Flag No. Pin Location

14'-4" from center of inclinometer ARC-1 (southern edge of crack).

2 and 3 11' from center of inclinometer ARC-1.

10 and 1/16" between the two pin flags.

4 and 5 6' from center of inclinometer ARC-1.

7 and 15/32" between the two pin flags.

6 6 and 1/16" from wood frame edge of the concrete pad.

GPS Coordinates N25.897884°, W97.496458° (northern edge of crack)

8 and 9 South 8’ from Pin 7.

11.5" between the two pin flags.

10 and 11 South 23’ from Pin 7.

14.0" between the two pin flags.

12 South 35’ from Pin 7.

GPS Coordinates N25.897672°, W97.496342° (northern edge of crack)

14 and 15 South 4’ from Pin 13.

15.38" between the two pin flags.

16 South 8’ from Pin 13.

The readings for each inclinometer are reflected in the graphical displays provided in Attachment A.

Attachment A includes both incremental and cumulative displacement plots. Attachment B shows the inclinometer locations on a Google Map.

The incremental displacement plot compares the mean deviation data to the baseline survey file. This plot reveals the exact depth where displacements are actually occurring. The cumulative displacement is the sum of the displacements from the base of the borehole. This plot shows the change in the position of the casing from the first set of readings.

The A-axis charts in the displacement plots show displacements in the plane perpendicular to the levee while the B-axis charts show displacements in the plane parallel with the levee. A positive reading in the A-

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axis chart indicates displacement to the west heading toward the Rio Grande River, and a positive reading in the B-axis chart indicates displacement to the north heading toward the Gateway Bridge.

2. Digitilt AT Inclinometer Digitilt AT system was used to survey the inclinometers. The system components include an inclinometer probe, control cable, a Bluetooth reel and the Digitilt Reader app for certified Android-based tablet computer.

The equipment is shown in Figure 1.

Figure 1: Digitilt AT System Components.

3. March 2017 Inclinometers Assessment

The depth of the casing restriction for the USACE installed inclinometers, I-32, I-33 and I-34 appears to be the same depth as the previous readings.

Data collected on March 17, 2017 followed the same trend as the baseline reading measured in June 2016.

The monthly displacement plots recorded between July through March are presented in Attachment A. Data comparisons for each inclinometer are described below:

Inclinometer Arc-1: The base readings for inclinometer Arc-1 were collected on June 22, 2016. The Arc-1 cumulative plot in the A-Axis direction shows a slight progressive movement starting at depths between 28 and 30 feet. This depth corresponds with the interpreted Alluvium/Pleistocene interface presented in Figure 2 of Arcadis’ December 2, 2016 Draft Geotechnical Assessment Report. This inclinometer will continue to be monitored on the normally scheduled frequency to determine if there is any increase in cumulative displacements. The displacement parallel to the levee are comparatively smaller and does not show any sign of movement in this month readings.

Inclinometer Arc-2: The base readings for inclinometer Arc-2 were collected on June 17, 2016. The Arc-2 cumulative and incremental displacement does not show any sign of movement on the plane perpendicular

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to the levee nor on the plane parallel to the levee. Although the cumulative plot in the A-Axis direction shows a slight displacement at depths between 40 and 42 feet, this displacement is not progressive. This displacement could have been caused during the curing of the grout or some other environmental factor after the initial reading.

Inclinometer Arc-3: The base readings for inclinometer Arc-3 were collected on June 17, 2016. The Arc-3 cumulative and incremental displacement does not show any sign of movement on the plane perpendicular to the levee nor on the plane parallel to the levee.

Inclinometer Arc-4: The base readings for inclinometer Arc-4 were collected on June 22, 2016. The Arc-4 cumulative and incremental displacement does not show any sign of movement on the plane perpendicular to the levee nor on the plane parallel to the levee.

ATTACHMENTS:

A – Inclinometer Plots B – Inclinometer Location Map

ATTACHMENT A

INCLINOMETER PLOTS

IBWC Arc-1 A - Axis

6/22/2016 11:22:30 AM 7/25/2016 3:17:20 PM

8/25/2016 1:34:40 PM 9/22/2016 1:35:22 PM

10/27/2016 2:18:50 PM 11/14/2016 1:34:00 PM

12/22/2016 3:53:53 PM 2/8/2017 9:25:00 AM

3/17/2017 12:20:09 PM

D ep th in

F ee t

Incremental Displacement (in) -2 -1 0 1 2

IBWC Arc-1 B - Axis

6/22/2016 11:22:30 AM 7/25/2016 3:17:20 PM

8/25/2016 1:34:40 PM 9/22/2016 1:35:22 PM

10/27/2016 2:18:50 PM 11/14/2016 1:34:00 PM

12/22/2016 3:53:53 PM 2/8/2017 9:25:00 AM

3/17/2017 12:20:09 PM

D ep th in

F ee t

Incremental Displacement (in) -2 -1 0 1 2

IBWC Arc-1 A - Axis

6/22/2016 11:22:30 AM 7/25/2016 3:17:20 PM

8/25/2016 1:34:40 PM 9/22/2016 1:35:22 PM

10/27/2016 2:18:50 PM 11/14/2016 1:34:00 PM

12/22/2016 3:53:53 PM 2/8/2017 9:25:00 AM

3/17/2017 12:20:09 PM

D ep th in

F ee t

Cumulative Displacement (in) -2 -1.5 -1 -0.5 0 0.5 1 1.5 2

IBWC Arc-1 B - Axis

6/22/2016 11:22:30 AM 7/25/2016 3:17:20 PM

8/25/2016 1:34:40 PM 9/22/2016 1:35:22 PM

10/27/2016 2:18:50 PM 11/14/2016 1:34:00 PM

12/22/2016 3:53:53 PM 2/8/2017 9:25:00 AM

3/17/2017 12:20:09 PM

D ep th in

F ee t

Cumulative Displacement (in) -2 -1.5 -1 -0.5 0 0.5 1 1.5 2

IBWC Arc-2 A - Axis

6/17/2016 6:27:13 PM 7/25/2016 3:57:11 PM

8/25/2016 2:02:22 PM 9/22/2016 2:05:40 PM

10/27/2016 2:44:45 PM 11/14/2016 1:57:25 PM

12/22/2016 4:18:54 PM 2/8/2017 9:52:21 AM

3/17/2017 11:58:39 AM

D ep th in

F ee t

Incremental Displacement (in) -2 -1 0 1 2

IBWC Arc-2 B - Axis

6/17/2016 6:27:13 PM 7/25/2016 3:57:11 PM

8/25/2016 2:02:22 PM 9/22/2016 2:05:40 PM

10/27/2016 2:44:45 PM 11/14/2016 1:57:25 PM

12/22/2016 4:18:54 PM 2/8/2017 9:52:21 AM

3/17/2017 11:58:39 AM

D ep th in

F ee t

IBWC Arc-2 A - Axis

6/17/2016 6:27:13 PM 7/25/2016 3:57:11 PM

8/25/2016 2:02:22 PM 9/22/2016 2:05:40 PM

10/27/2016 2:44:45 PM 11/14/2016 1:57:25 PM

12/22/2016 4:18:54 PM 2/8/2017 9:52:21 AM

3/17/2017 11:58:39 AM

D ep th in

F ee t

Cumulative Displacement (in) -2 -1.5 -1 -0.5 0 0.5 1 1.5 2

IBWC Arc-2 B - Axis

6/17/2016 6:27:13 PM 7/25/2016 3:57:11 PM

8/25/2016 2:02:22 PM 9/22/2016 2:05:40 PM

10/27/2016 2:44:45 PM 11/14/2016 1:57:25 PM

12/22/2016 4:18:54 PM 2/8/2017 9:52:21 AM

3/17/2017 11:58:39 AM

D ep th in

F ee t

IBWC Arc-3 A - Axis

6/17/2016 7:05:22 PM 7/25/2016 4:28:56 PM

8/25/2016 2:41:46 PM 9/22/2016 2:36:13 PM

10/27/2016 3:17:17 PM 11/14/2016 2:27:09 PM

12/22/2016 4:38:15 PM 2/8/2017 10:12:24 AM

3/17/2017 11:40:50 AM

D ep th in

F ee t

Incremental Displacement (in) -2 -1 0 1 2

IBWC Arc-3 B - Axis

6/17/2016 7:05:22 PM 7/25/2016 4:28:56 PM

8/25/2016 2:41:46 PM 9/22/2016 2:36:13 PM

10/27/2016 3:17:17 PM 11/14/2016 2:27:09 PM

12/22/2016 4:38:15 PM 2/8/2017 10:12:24 AM

3/17/2017 11:40:50 AM

D ep th in

F ee t

IBWC Arc-3 A - Axis

6/17/2016 7:05:22 PM 7/25/2016 4:28:56 PM

8/25/2016 2:41:46 PM 9/22/2016 2:36:13 PM

10/27/2016 3:17:17 PM 11/14/2016 2:27:09 PM

12/22/2016 4:38:15 PM 2/8/2017 10:12:24 AM

3/17/2017 11:40:50 AM

D ep th in

F ee t

Cumulative Displacement (in) -2 -1.5 -1 -0.5 0 0.5 1 1.5 2

IBWC Arc-3 B - Axis

6/17/2016 7:05:22 PM 7/25/2016 4:28:56 PM

8/25/2016 2:41:46 PM 9/22/2016 2:36:13 PM

10/27/2016 3:17:17 PM 11/14/2016 2:27:09 PM

12/22/2016 4:38:15 PM 2/8/2017 10:12:24 AM

3/17/2017 11:40:50 AM

D ep th in

F ee t

IBWC Arc-4 A - Axis

6/22/2016 10:48:04 AM 7/25/2016 5:08:42 PM

8/25/2016 3:15:23 PM 9/22/2016 3:09:20 PM

10/27/2016 3:58:37 PM 11/14/2016 3:00:46 PM

12/22/2016 5:00:01 PM 2/8/2017 10:34:24 AM

3/17/2017 11:22:03 AM

D ep th in

F ee t

Incremental Displacement (in) -2 -1 0 1 2

IBWC Arc-4 B - Axis

6/22/2016 10:48:04 AM 7/25/2016 5:08:42 PM

8/25/2016 3:15:23 PM 9/22/2016 3:09:20 PM

10/27/2016 3:58:37 PM 11/14/2016 3:00:46 PM

12/22/2016 5:00:01 PM 2/8/2017 10:34:24 AM

3/17/2017 11:22:03 AM

D ep th in

F ee t

IBWC Arc-4 A - Axis

6/22/2016 10:48:04 AM 7/25/2016 5:08:42 PM

8/25/2016 3:15:23 PM 9/22/2016 3:09:20 PM

10/27/2016 3:58:37 PM 11/14/2016 3:00:46 PM

12/22/2016 5:00:01 PM 2/8/2017 10:34:24 AM

3/17/2017 11:22:03 AM

D ep th in

F ee t

Cumulative Displacement (in) -2 -1.5 -1 -0.5 0 0.5 1 1.5 2

IBWC Arc-4 B - Axis

6/22/2016 10:48:04 AM 7/25/2016 5:08:42 PM

8/25/2016 3:15:23 PM 9/22/2016 3:09:20 PM

10/27/2016 3:58:37 PM 11/14/2016 3:00:46 PM

12/22/2016 5:00:01 PM 2/8/2017 10:34:24 AM

3/17/2017 11:22:03 AM

D ep th in

F ee t

ATTACHMENT B

INCLINOMETER LOCATION MAP

Pin #1

Concrete Pad

(2'x2'x4")

Pin #6

Pin #2

Pin #3

Pin #4

Pin #5Arc-1 (B-1)

I-32

I-33

I-34

Arc-2 (B-2)

Arc-3 (B-3)

Arc-4 (B-4)

Pin #7

Pin #9

Pin #8

Pin #10

Pin #11

Pin #12

Pin #16

Pin #13

Pin #14

Pin #15

REMEDIATION DESIGN OF LEVEE FLOODPLAIN FAILURE

WITHIN THE UPPER BROWNSVILLE LEVEE REACH

LOWER RIO GRANDE FLOOD CONTROL PROJECT

INCLINOMETER & LEVEE CRACKING LOCATION

ATTACHMENT

B

IBWC

SUMMARY REPORT OF INCLINOMETER READINGS